How to sell beats online?

I'm a musician who would like to start selling beats online. Question
is, how do I go about getting a contract written to lease/license my
beats? I see a lot of idiots selling beats online, but I don't know
how they ever acquired a legal contract to legitimately sell beats
online? So how can I get one written up? Is a lawyer the only way to
go, or ?
A license is required. Unless I want people to jack my beats. I need a
license. I know where to post my music to sell it, I just need to know
where I can get legal documents to legitimately sell them to people.