As for the answer from bryris , he MAY be correct or not. It depends on YOUR club rules. MOST clubs will let you fly whenever you want once you have solo'd but you need to make sure as not to break a rule. It is also very wise to have someone there that can either drive you to the hospital or at least dial 911 in case of emergency. The list of things that could cause injury requiring medical attention is too long to go into and common sense says not to fly alone. It is difficult to hold a bandage on an artery and drive at the same time, especially if unconscious. IMO
Some clubs have limits on hours of operation to keep the neighbors happy too. You should be fully briefed on all club rules and policies in the near future, if not ASK.