The TT46 pro is a good choice.
It's a strong engine that starts easily and run good. It'll be a good first engine for your trainer and powerful enough to later go into your first 40 sized sport plane.

Fuel is a very popular subject for discussion and everybody have their own favorite or idea on what to use.
As a beginner I'd recommend you to buy a gallon of fuel at your hobbyshop, choose a brand named fuel with 16-18% oil and 5-10% nitro (you really don't need to over analyze what's in there, it will work )

Good luck and welcome to the RC forum.