I have a red spot on my foreskin with a tiny black dot. what could this be?

See derm: See dermatologist for possible biopsy. This would tell you what this is.

See your doc: This is a problem that requires a face-to-face meeting with your doctor. In that meeting, your doctor will listen to you, perform a throrough examination and possibly order labs or other tests. Based on this information, he/she will be able to tell you what's wrong and what to do about it.