I still don't get sentiment against lock using keys. Just put those keys, just one if you get the same keyed ones, on the same key ring with your house keys and store the spare key separately. This way whenever you leave you would have all the keys with you! Plus it's easier to unlock when you really need it
People already mention to get cleaning kit. Remember to get some kind of cleaner and oil or CLP like stuff. Personally I use Ballistol. Also you need eye protection as well, especially if you plan to shoot steel.