What is the perfect diet? Any advice?

Okay, so I have decided I want to diet or at least eat more healthily, any tips on what to eat? Like what's the best fruits and other things to eat that will keep me healthy and will help my growth, I have been going to runs and stuff, and I go to a dance school 3 times a week, so I have just been staying the same really because I realise that I haven't got the best diet really.. Me and my mom are going out shopping tomorrow or maybe even tonight or the the next day to buy in all the healthy stuff I want for my diet as she is doing it with me, anything that really does work? And preferably things that taste nice as well, haha! Help please:)?