I got him about two months ago at a poor qaulity store (in my opinion). he's an older bird and a VERY, VERY nervous parakeet

It also looks as if he is missing a toe

I set his cage near a window, and thats where he basically lives. I want to teach him how to say his name and a tone or two. But with him being a store bought bird, is this possible? Also, is it better if he lives by a wall, then by a window?