RE: Alpha Trainer RTF
I also learned to fly on the Alpha trainer. Excellent beginner's airplane. I also recommend the 60 size (didn't have it when I learned) as it will be easier to see and can be flown in light winds.
Once you break the prop, and you will, just replace it with a two bladed propeller instead of trying the find three bladed props that fit. 12X6 should work fine.
Keep the airplane at least 3 mistakes high and close enough to you so you can see it clearly.
If at all possible get an instructor.
Good luck!
Regards,
doubledee