Find something to fix and, well - fix it. No matter how difficult or time consuming it is, it'll at least give you a perspective into where problems truly are. There are loads and loads of addressable problems which may not fix anything now, but it can set the foundation for ten years from now. Voting isn't your only course of action.
Finding ways to fix niggling class/social/economic issues is a great start and I highly recommend that you try. My personal project along these lines is to find invalidly created parking tickets in Chicago. The hope there is that it will reduce the stress of lower income communities and give them a bit more financial freedom to get out of bad situations.
If you want to talk about this more, I'd love to - hubblefisher at gee mail