You will need a good pair of basketball shoes. Higher cut shoes provide more ankle support and can help cut down on injuries. Shoes should be primarily black and brand does not matter.
While the team will provide basketballs for practice, it would still be a good idea to have a basketball to use outside of practice. Many drills to improve ball handling and shooting can be completed outside of practice and many do not require access to a goal.
Players need to have shorts and their practice jersey each day at practice. Their hair should be pulled up or out of their way and jewelry should not be worn. Knee pads are optional, but if you plan to wear them in games it would be good to get used to them in practices.
Each player needs their own water bottle to use for practices and games. Individual water bottles help reduce the sharing of germs and illness.