I learned to fly when I was very small on an 1/2A Ace Alpha. It had a wingspan of about 30 some inches I guess and landed in the grass without landing gear. I didn't think at the time it seemed small. I took a break from flying while in school, and then learned the full flying skills, runway landing with gear on a 20 sized Goldberg Freedom 20. It is a little smaller than a "normal" 40 sized trainer but the difference went without notice. It flies just as smoothly and could fly it away jut as far as larger trainers. I think you'll be fine with just about any size plane as long as you have someone helping just in case.