Depends on the time you have/desire you have to actually build your first plane. I like building planes, and if you're the tinkering kind, you'd probably enjoy the FT style foam board route. If you are just looking to try flying without committing to the full jump into the hobby its hard to beat something like this...
I've still got mine, flew it till the servo's crapped out, gutted the RTF gear and installed a cheap DSMX receiver, servos, and brushed ESC. Flew that till I burned the motor out, and so now its brushless LOL
Its a durable airframe and pusher setup means you won't break props. It comes as 3 channel but its made so you can cut ailerons into the wings when you're ready for 4 channel...
There are better planes to be your first, but there are more that would be far worse.
The A-10 has relatively light wing loading with dihedral and has the ability to fly slow, yet enough power to get you out of trouble. These are good traits for a trainer.
If you want to get into flying and are passionate about the A-10 there is no reason it couldn't be your first plane. My first plane was the FT Seaduck and others told me I should pick something simpler, but it was the plane I was passionate about. When getting into a hobby you need to be excited about it, and if flying the A-10 does that for you, go for it.
However with that said, you don't want to fly something you aren't ready to crash. If you have someone to help you and buddy box you while you are learning you should be fine. If you are planning to go out to a park and learn to fly on your own, you will be rebuilding this plane... probably a lot. Just remember, when you crash (not if) hot glue, popsicle sticks, bbq skewers and scrap foam can fix quite a bit of damage.
As others have mentioned, the A-10 COULD be a first plane for you; however, it's got a few things that make it a bit more challenging for first time fliers - differential thrust, and a low wing, give it different flight characteristics than those of say, the Bushwacker or Simple Cub. Does that mean that you CAN'T make it your first plane?
I was like @Horseman3381 - I started with the Sea Duck as well, as my first build. However, I'd had a lot of flight time with quadcopters on a simulator, and then time flying our club trainers, which were Apprentices. I was fairly comfortable before I put my Sea Duck up on the first flight, and had a club member maiden it for me and trim it out, before I started flying it.
It had its quirks, and flew differently than the Apprentice. Was it a good first plane? For someone who was used to flying 4 channel, YES. If you've not had experience with using rudder/differential thrust/yaw to turn a plane? I wouldn't recommend it. and since the A-10 uses a lot of those same principles to turn, you'll encounter similar characteristics. In addition, the low wing (one mounted under the fuselage, as commonly seen on the warbirds or racers, as opposed to a high wing, common in Cubs, the Bushwacker, Tiny Trainer, etc) wants to have a bit more speed over the wing to keep it aloft, meaning your reaction times have to be a little sharper. Now, that might not be an issue for you, but if you ARE teaching yourself to fly and are still trying to get used to things like "left is right and right is left" when the plane is coming at you, then you might want a plane that's more forgiving and will fly a little slower.