Apply pressure to to the cut to help prevent bleeding. If you cannot control the bleeding, see your dentist or go to the hospital emergency room. Stitches may be needed to close the cut, help prevent infection and promote healing.
Tiny chips may only require reshaping and polishing. If the fracture is small a composite (white filling) may be bonded in place to replace the chipped area. Larger fractures may need a crown and if the fracture involves the nerve, a root canal will also be needed. More extreme breaks will need extraction and replacement with an implant, bridge or partial.
A mildly loose tooth may require no treatment and tighten up on its own. When they are too loose or malpositioned your dentist will bond it to the surrounding teeth for support until it heals. A traumatized tooth may darken or develop an abscess. This could happen immediately or years later. An abscessed tooth will require a root canal and a crown. The only other option is to extract the tooth.
Do not wipe the tooth clean. Place the tooth in a wet napkin (good), in a glass of milk (better), or in your cheek (best). These help maintain the integrity of the tooth for reimplantation. See your dentist immediately. Sometimes if it is placed back in its socket soon enough by your dentist it can be saved. The sooner you can get the tooth back into position the better the prognosis.