First…if you think you should see a Dr. then do so. If it is bleeding apply direct pressure. Do not apply pressure of broken bones or over bones sticking out of the skin. If you have broken bones seek further medical attention. If you don’t think it is bad enough to require going to the hospital then…make sure it is clean and that it stays clean. Make sure all road debris is out of the wound, you can wash it with mild soad and water or an antiseptic rinse of some kind. Most important is to keep it clean until it is fully healed. Once bandaged do not keep removing the bandages. This will help cause it to open back up and bleed more. The elbow is a difficult spot for that though. Every time you bend your arm the scab will break open. Keep and anti-bacterial (such as Neosporin) on it to help keep it clean, moist and germ free. It sounds like you are going to need more medical supplies. If they aren’t available to you don’t worry about it. It does not have to be covered. Covering the wound will simply help to keep in clean and keep you comfortable. Good luck and I wish you a speedy recovery.
Do not use paper towels to cover the wound if you can help it. They can break appart and place more debris in the wound. If you need to have it covered until you can get more medical supplies old, clean clothing or towels will work. Just make sure it is some thing that you don’t mind cutting up and throwing away.