Ok couple of things to check. Because the Ender 3 has only one z motor, its very important that the x axis gantry is level and that the rollers on the ends are adjusted properly. They should be tight against the rails but should still be able to rotate by hand. There are a couple of eccentric nuts that adjust the rollers. Measure both ends of the x rail to the bottom frame as a reference point. Then check your bed rollers and again , they should be tight but not too tight. Next check the bed to make sure there is next to no rock on it, if there is , check the bolts that hold the y rail to the frame. Once this is all done, then level the bed with a piece of paper and you should be ok. Once you get printing more you will probably want to turn on "baby stepping" and "mesh leveling" in the marlin software but that can come later. Google and youtube vids are a great source of info.
Your print head should be close enough to the bed when homed that a standard sheet of paper will slide with some resistance between them.
If your printer does NOT have an auto leveling system, you adjust this by homing the printer through menu then adjust the bed level using the bed adjustment wheels to get to the desired level. Be sure to disable steppers and check all four corners to make sure the whole bed is leveled.
If your printer DOES have an autolevelling system you will have to auto home and then adjust the "Z offset" value, usually found somewhere in the printers menu system, until you have the right value.
No amount of glue will help if the head is too high.
@Aslansmonkey, your getting some good advice from members. I have a CR10 printer that I use for single wall ( 1 perimiter) prints. I too struggled with leveling and getting prints to stick early on in my printing experience. I've been printing about 5 years now and trial and error has managed to get me to the point of success where I very seldom have a print fail to print due to adhesion.
I print mostly Pla and lw-pla. My first issues were with the Creality glass bed being slightly warped, which was an issue with the earlier. Cr10 printers. I pulled off the glass bed and measured the clearance between the nozzle printing surface and the plate that holds the actual bed in place I used the print head as a reference and used a "automotive feeler gauge". To see if while moving around the print head and measuring the space between the base and the print head was consistent from one area on the printer to the other. This is like using the paper to set your clearance between the print head and the bed, but you are actually checking to see if the mount that holds the glass bed or what ever surface you are printing on is level on the machine. Mine was not! No matter what I did to level the bed solved the problem until I discovered that the Creality cr10 has a "spider" mount system that supports the aluminum bed mount and then the glass. This "spyder" was slightly bent in shipping so no matter what I did for leveling, including replacing the glass bed helped cure the problem.
What did cure the problem was this;
I removed the glass plate, removed the aluminum bed
I homed the machine so that the print head was in the home position and then deactivated the motors so the print head could be manually moved around the print area, checking the gap between the print head and the "spyder" arms that usually hold the knobs, screws and springs that are part of leveling the bed.
Doing this, have a clear sight that, that part of my machine was bent a few thousand and needed to be straightened (leveled) before I could reassemble the bed and glass printing surface.
So in my case, a bent mount that holds the leveling mechanism, was a cause of not being able to get a level bed. The glass printing plate had a "dip" right in the center causing an improper gap to occur in the center of the print bed too large,and my single prints printed right in the center of the bed would not stick.
Finally, I replaced the reality cr10 glass plate with a mirrored glass Tile from homedepot, After reading about the glass plate coming from the factory with a dip in the center. I measured that there was about o.15 thousands more clearance in the middle of the glass plate and the print head. I "padded" the low area at the center of the aluminum bed with some 5" discs I made using aluminum foil and stacked them like thin pancakes on the center of the aluminum bed and put a stripe of masking tape in an "X " pattern over the aluminum foil , (I even considered the thickness of the tape). Once I had all the aluminum shims in place I was able to measure all clearances with a paper gauge as described here. The aluminum foil I used was straight from the kitchen cubbard.
I do use a 12x12 inch mirror for the print bed still and it has continued to give me good adhesion with the use of aquanet HD hair spray and bed adhesion and leveling problems have become a thing of the past.
I am still using the same springs and find that they are holding well to the point where I don't desire an automatic bed leveler.
Some of these ideas may help you with your machine.
If your printer is all together and ready to print minis the filament,
Turn on temp to the bed to say 60 degrees C
Turn on temp to nozzle to the recommended temp for the filament. I run my pla hot between 200 and 230 c.
Your printer should heat up and be ready to print***** , at this time I have not put the PLA filament in the extruder***** The extruder is empty and not dripping hot plastic out of the nozzle . This is
so that I can use the paper as a gauge to test the clearance between the nozzle and the glass bed plate and not have bits of plastic in the area to be gauged.
once I have moved the nozzle around from "home" to corner to corner, and to the center of the print bed. I used the paper strip to test the level and once I am satisfied that the bed is level, I add the filament into the extruder until it bottoms out in the heat chamber. I would then attempt to print the files I had loaded into memory.
If you first print one of the files from Thingiverse that show you the condition of your bed leveling you can determine if your print is consistent, (level). If the print is thick or thin at one corner or the center, you will have a good indicator of the flatness and set up. These machines are remarkably accurate once set up, don't get discouraged! Also, the age thing, you will conquer 3d print, I'm 79 years young myself, "We", just don't do things as fast as we used to when we were young. Yes, computer smarts can help, but you will learn as you go and at this time in your life there are many willing to help. Take care, and keep asking for help along your adventure.
pS; you want the paper gauge to slightly drag when you slide it between the nozzle and bed.
If the paper bunches up or wrinkles, the gap is a little too tight. Use "fresh" paper strips about 2 x 3 inches cut from 20 lb bond paper, like out of a computer printer. Most are consistently two thousandth thick.
Like you, I've been 3D printing for 4 years or so now. I've even built a few 3D printers from scratch using Ramps boards and Marlin. I just picked up an Ender 5 Pro Plus to replace my aging Monoprice Maker Select.
You bring up a good point though, with your issue on the Y Axis tray. Sometimes these things are out of whack and this is why I don't recommend 3D printing to anyone who doesn't have the patience to tinker a little. You need to invest a little effort and time to understand how things work because you will need that investment to KEEP things working. Even my brand new Ender 5 needed the Z adjustment set after putting it together. That kind of thing can't be adjusted at the factory. And I couldn't even do that because the auto level wasn't working (had to switch the probe in the BLTouch out with the spare one that came with the printer).
But it sounds like the OP's issue is with that initial Z adjustment, not (necessarily) with a warped bed.
Though my Maker Select probably has the warped bed issue you had, just not as pronounced.
I want to give you guys a little update on the printer. Maybe this update just might help someone. I have been doing some thinking about the Z axis limit switch. This is what I came up with. Creality wants you to adjust the Z switch by moving the switch up against the Z rail till the switch just clicks, then tighten the bolts on the side of the switch. For some reason I pushed the Z switch up to far. By doing this it created more distance from the bed to the nozzle when in the home position. I re-did the whole leveling procedure and made sure the Z switch just clicked. Everything is good now.
Thank You guys for your help.
Thank You @ jobobeda for words of encouragement. Always willing to learn something new. I believe this is the key to staying young.