Do you want to stick with the foam electrics or are you looking to get into glow powered airplanes?
If you are wanting to stay with the RTF foamies then it sounds like you have a good trainer if your dad lets you use his Super Cub. You could always get your own but you might want to wait and purchase your own intermediate airplane. Some options might include:
http://parkzone.com/Products/Default...ProdID=PKZ4475
http://www.horizonhobby.com/Products...ProdID=EFL2725 (this is also a trainer but it is larger and has ailerons unlike the Super Cub)
If you are wanting to get into glow airplanes then a good trainer would be the place to start:
http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXCXF4**&P=0<br type="_moz" />