I taught myself on a Cox .049 powered trainer with a 39 inch wingspan, and had total success with it. It was light and suffered little to no damage when I crashed; it was slow and easy to fly, engine was easy to start by hand. Trouble is, short of scratch building or converting an electric, I don't know how you'd do anything like that now.

I think the best I've seen out there is probably the Sig LT-25. A friend in the club had one and he loved it even after he got pretty experienced. He had a plain bearing 25 on it. Plenty of power, 4 oz tank, a gallon of fuel lasts all summer. I don't know if you can even buy those engines anymore new, unless you pick one up on the trader forum or buy on ebay. There must be tens of thousands sitting in drawers, so if you join a club someone will probably sell you one cheap.

Once I started flying with engines larger than my Cox I set up a test stand so I could get used to starting and adjusting the engine at home before I put it on a plane and took it to the field. I highly recommend that. I go to the field to fly, not to fuss with engines.

I flew that little trainer by myself for a couple of years and then joined a club. Never regretted either one. Joining a club and getting some instruction is a good idea. I had flown free flight and CL before, so I learned on my own easily, but most people want and need an instructor.