TooBlue, you can totally salvage this build, it doesn't look too bad at all. Especially for a first time build.
First off, the chest plate and back plate aren't connected, so some strapping over your shoulders will fix that. The shoulders look ok as is, so don't beat yourself up to much.
I'd add a strap under the arms to attach the back to the chest. That will prevent it from sticking out like a crazy back wing.
The paint job could use a (slightly) lighter color green to add effect, then go over it with clear matte finish, and it'll look better.
You got this, man. It looks good.