Exercises to train my core and lose tummy fat?

So im in grade 10, and weigh about 150 pounds. My calfs, however are solid muscle (about 37 cm), because im a highland dancer. I also participate in kickboxing. Basically, I want to help train my core, and get my tummy flat... any detailed exersizeswould be greatly appriciated. =] I'll give you my first born son!! xD <3