What are the symptoms of sexually transmitted infections in general?

Numerous. Too diverse and complicated to go into in a brief paragraph. If you fear, however, that you may have been the unfortunate recipient of an std, go see a doctor, get tested extensively and in the future be very very careful. Good luck.
None to many. Often, STD's don't have symptoms. When people do have symptoms, they range from having a discharge, itching, bumps, growths, abdominal pain, and burning while peeing. If oral or anal sex is involved, then symptoms can happen at those sites as well. If you've had unprotected sex, esp with a new partner, get yourself tested! Good luck.