What did you all do together? Were any condoms used?
Chances of getting herpes from a one time encounter are pretty low, especially if there is no active outbreak. Chances go down even lower if a condom is used. Unfortunately, we have no same-sex studies on transmission rates, so I can't give you exact numbers, but it's pretty low.
I wouldn't be worried if you don't develop any symptoms, like blisters. A red dot with no pain, itching or pus isn't herpes. I can't say what it is, but if you are concerned, have a doc look at it.
If you had unprotected oral, you can get syphilis (whether you gave or received), or gonorrhea (if you gave, you could get it in the throat, or in your urethra if you received). Syphilis rates vary from location to location, as do gonorrhea rates, but it wouldn't hurt to get checked for that. Rates for both are always higher in men who have sex with men, unfortunately, even if chances are low overall.