Help me find a way to make this happen?

I recently moved from a city to a small town and Im liking this girl. We have a cl of sixteen. Shes very queit but not really shy. Shes lived here since birth, problem is I have been told she has had problems hanging out with the wrong crowds being talked into drugs and . I want to protect her but we arent more the conversationalists and she has a older boyfriend who is rumored to have ped some stds. I care about her And Want a plan of action, any Ideas? her best friend has turned into a -loving skank who absolutely disgusts me. I know shes not bad because my sister has told me she never makes fun of anyone when her friends do. I want to do something about the major drug problem in the town(it's bad enough the place has been under police investigation). What should I do?