How can i eat healthy (teen)?

so im not fat not even chubby, just wanting to tone up,get in shape,and be more healthy. i realize i need to eat healthy to lose some wieght so mu muscles are visible,but my family really eats all processed food. we dont eat out much.i only drink water. but what are some healthy alternatives to snack on.i usually eat ice cream, or little debbie snacks for snacks . also what are some alternatives to running for cardio?