Not really a need to learn theory to play a few notes. If you want a great bass line, then you need a great bass player. You are just looking for a simple track, so do it yourself. I can only assume you have no musical knowledge, based on the question, so I will suggest again, that you find someone who does, and have them play something for you. Or just make a 'bassline' yourself.
Dood, if you are tone deaf to the point that this does not make sense, then you really might want to look into a different form of expression.