Are there any teen travel programs for the summer that I can go on? I am 15 years old and my parents really?

don't have a lot of money, but i need something to do this summer and I also need college credit, and i truly enjoy volunteering and i am reallly good with kids. Can it be a place where it looks like fun because most likely im going by myself and want to make new friends there, but I don't want to be lonely. Also, I would love to travel somewhere like Brazil, or Spain but if thats expensive i wouldn't mind mexico or colombia, or costa rica or anything. Please help me ...