How big is your back yard?
A nitro plane needs a very big area to fly in.
Nitro trainers can land on pavement or mowed grass. you will need about 100' wide by about 300' plus for a beginner to land in and no trees for another 200' in any direction. Our tightest field, and I hate flying there, is about 100' wide and about 400' long and surrounded by trees within 100' at each end of the runway and at the edge of the field on the side.