Is there anything I can get from the grocery store or drug store for a cut on the ear until I can see a doctor?

Sure. Assuming you don't need stitches, clean it with soap and water and apply an antiseptic cream like neosporin or bacitracin. Band-aid therapy may be indicated. If the bleeding won't stop or the wound is gaping, you'd be better off having it looked at.
Antibiotic ointment. Use antibiotic ointment twice a day on your cut. Please make sure you keep the cut clean.