Last year the game fee was $200. They pay no travel. So your travel time depends on where you live and how fast you drive.
The closest game site to me is in NYC, about 2.5 hours by car.
Your schedule is up to the supervisor, obviously. Depending on your availability and your experience, you could receive anywhere from 2 games to 15 or 20, I suppose. USBL uses 2-whistle crews, so I don't even know if they're hiring this season. When I contacted the league office about 2 months ago, they did not have a Supervisor of Officials in place.
Hope that helps.