How can I make a professional soccer league?

The question is not how, but why.

You'd be better off just starting your own team. The American soccer pyramid is already set according to the US Soccer Federation, and that's the body you get into FIFA through. MLS is Division 1, the North American Soccer League is division 2, and United Soccer Leagues USLpro is Division 3.

Everything else is going to be amateur soccer at best. United Soccer League operates a number of amateur divisions , a women's league and youth developmental soccer. That's probably your best bet.