Get healthy!!!??????!!!!!!!?

ok so i am 14 and naturally really thin.so my diet is NOT healthy at all,whatsoever.it pretty much consists of pasta(with only parmesan cheese),bread,chips,chicken nuggets and fries.i am actually a really picky eater.its horrible and my parents do care....but its kind of like theyve given up on me being healthy...because im so picky.but lately ive been really wanting to basically chabge my lifestyle and eating habits.i want to prove my parents and friends that i can become healthy.but HOW? also,foods that will keep my hair hair healthy and shiny!!thanks(: