While starting a football club can require a ton of effort, stepping onto the field with your team will more than be worth it. Unlike some sports like basketball, fielding a football team requires a wide mix of athletes, assuming you want to play something that resembles a professional game. In addition to a lot of work on the ground, you'll want to put the latest online resources to use as well in forming your club.
Depending on the size of your town or city, there may already be an adequate structure in place for starting a football club that can join an existing league. Around the country there exist many amateur and semi-pro clubs that compete against other teams in a given city, state or region. While joining a bigger league may require a large financial commitment that you may be unwilling or unable to fulfill, many smaller leagues have open admissions and are probably dying to get some new blood in their leagues. Even if you don't have any of these in your region, don't worry; you can still successfully form a club without one.
Your next step will be to build up and gauge interest in your football club. If you've already been on a team in your area and have a community of football players, then this process will be much simpler. In all likelihood, you won't have trouble tracking down a few friends who want to play on weekends or on a weeknight. It's most likely, however, that this pool of athletes won't provide enough players to field a team.
Consider flyering in places where football players in your town hang out. A good place to start is the gym, as many former players like to stay in shape. Also consider local sports bars, restaurants, malls and really any place with a lot of foot traffic. If you live in a large area, you may find more success using an online tool like Meetup or Facebook, where you can very quickly find locals interested in playing on your team.
After you've gathered a group of men (and maybe a few women) who want to play, you'll need to decide what style of football you want to play. If you have competition in your area, you may just need to field a single team, selecting the best players who expressed interest. On the other hand, if you need two teams in order to compete, you may need to field smaller teams using the members of your club. In most informal leagues, all players are expected to play both offense and defense, but if you find enough members this may not have to be the case.
Once you've got your club membership pinned down and a few games on the schedule, you should seek out local businesses that are willing to sponsor your team. Oftentimes, local restaurants are willing to purchase jerseys or shirts for your team -- and maybe a few pads or helmets -- in exchange for placing their logo on your gear, especially if you're willing to have your post-game celebrations there every week!