Have you got a garage? Have any of your friends? Get some mats, or if you can't afford them, some soft foam sheets. Cover the floor and train! I was a 3rd Kyu brown belt when I started teaching Aikido (that is so far back
)! Though make sure you get written and signed agreements that they will not take action against you for injury, or make sure you all get insurance. DON'T even think about going near real knives or katana!!!!! Use wooden tanto and bokken!
Hope that helps.