Trying to find birth parents?

I want to try and find my real parent's , my adoptive parent's don't really have much information about them apart from my birth mothers first name and a picture of her. I'm 16 , and I really want to find them. I know the reason why she put me up for adoption (it was right after birth). I've looked at a couple of website's and they all made be pay a fee and I thought some of them could be trying to take advantage of people or something. I'm not sure what adoption agency it was under , seeing as it was done in Arusha,Tanzania (Africa) so things might not have been as smooth as they could've been. Would it be worth calling up the hospitals I was born in and ask them for names or something? Or is it worth trying to find them through an agency? I really have no idea here guys , and I really want to find them.