How to give shoes better traction?

I just started my second semester gym cl and have been having troubles. I was losing balance while running in the gym a few days ago. And today I actually fell while chasing the puck in hockey. I can be clumsy sometimes, but I can definitely feel myself slippin on the gym floor. I have a pair of Vans shoes, but don't wear them to gym cl. I wear a pair of gym shoes that used to be my brother's. I found them a day before I had to dress for gym. So I don't know what to do.