In addition to expecting you to provide your own equipment, many teams also require you to pay dues. The costs vary from team to team and could amount to a few hundred dollars a season. Luckily, your dues don't always have to come out of your own pocket. Many teams allow you to find sponsors to cover the cost.
Some teams also have a community service requirement, at times putting their brawn to good use. The Southern Maine Raging Bulls offer a moving service for single mothers and the elderly who need help with large items. Whether it's helping out a couple of hours a month or at a semi-annual event, you may need to budget extra time to fulfill this requirement.
Travel is an inherent part of the sport, and players should expect to cover most of their travel costs for the half of the season they're traveling.
Practices, community service, travel. It sounds like a lot of time. How much of your schedule will semi-pro football dominate?