Anyone can join a club here at Hogwarts! To be a President though you must be a seventh year and give us a few reasons why your character should be President. The same goes for Vice President except you can be a sixth year for that position.
+ We've had questions about what the Booster Club is. It's to develop support and spirit among the student body for Quidditch. They go to games, make signs, boost morale and hold fundraisers if possible to get money for the program itself.