Some STDs, some not. Only general advice can be given without a photo or physical exam. Top 2 photos are non-STDs: Fordyce spots (sebum which can be extricated by M.D. or left alone), Infected hair follicle
(plucked and kept clean). Bottom 2 photos are STDs (HPV
and Molluscum) to be evaluated by your MD so s/he can rule out other STDs and council you for prevention.