RE: Hobbico RTF Planes
Avistar is a great trainer plane. There are tons of threads here to confirm that. As your skill level progresses, you can modify the plane and convert it to a tail dragger, enlarge the control surfaces, etc to make it a little more challenging.
As for the construction of ARF's and RTF's, the majority are great. You will always have a couple slip through where you might have to secure the covering a little better or get rid of a few rinkles, but nothing major. Whatever you do, have an experienced pilot do a ground check before it flies, and also have a trained pilot take it on its maiden flight.
And at 15, start now, don't do what I did and wait til your 42. Have fun!!! Good luck!!! Better get a job now to pay for that fuel.