Excercise for a teenager

Hello, I am 14 years old and 4"11. I wigh about 85. I get picked on a lot and people call me anorexic. I know this isn't true, and I shouldn't let it get to my head. But, I really want to get stronger because it may mae people think better of me.

I want to make an exercise routine that fits my hard work schedule. I have a few weights, and I want to learn how many push-ups/sit-ups to do. I also want to know if it would be unhealthy to do other things, like running on a treadmile. Thank you!

PS What is the average weight that I should be