mining is a competitive thing, so you will need a competitive set up to be able to be a valid part of the mining operation! you can't start it with only 1 GPU and a GPU which is rather old. your GPU will give you about 240 Hash/s while other newer ones are getting 10-1000 of Mhash/s.
you can find a bunch of good information about that here:
https://miningchamp.com/mining is still an option which can be a good one too, you mine altcoins with GPU by the way. but it depends on your equipment and the costs such as electricity cost that you have to come to profit.