OK, I'll be the guy to SOUND all condescending.
How do you get to Carnegie Hall?
Practice.
Don't expect your first build to be your Magnum Opus. There is no problem with downloading some of the easier designs, the simple swappable motor box and Delta wing planes OR the chuck glider ones, printing them out, transferring and building several of those If only to scrunch them up, put them in the trash and try again. (Actually, build another one looking at what is sketchy about the previous and correct it). It's only going to cost you a couple more pieces of foamboard AND when you get the construction part done, you can try finishing part of hitting them with PolyV, wiping it and making it fuel proof. Then painting it. THEN you can scrunch em all up, pretend you're a natural and build that fancy one looking good. Or, you know, Just get it good enough to fly and enjoy. The next one will be better. And better and Better if your like the rest of us. Or ANYONE in an apprentice type of job. Woodworkers used to start making joints then after grading, throwing those in the fire and making more. and more. till they got the joints right AND I hear that in Japan you can expect to be making rice for several years before they think you know what you're doing. Well that's what I heard on one of the cooking shows my wife is always watching.
When she's not watching one of those "Whoops, I killed my husband" detective shows.
Sharp tools, the right tools, the right glues and glue guns and Practice.
It's not a race. Its an adventure.