There are not many online money making opportunities for teens, as most of the opportunities are specific to adults.

However, there are many survey companies that allow teens to complete surveys targeted at them, and then they pay you every other week.

If you are 13-17, you mostly need permission to join some of the survey companies, but everything is legal and legitimate and you should have no problems earning some cash on the internet.

For survey companies that cater for teens, check out Teens can make money