Hi i'm having a reddish color hard pimple on my penis head but not paining or itching and another pimple on the scrotum itching what can that be?

It's difficult to diagnose without images or a well description of the lesions. However, if your are sexual active and you do not use protection, genital warts due to HPV infection could be the case. You should see a dermatologist if possible or at least your family doctor and use condom in the mean time.

If you had no sexual exposure then clan it with soap and water and apply OTC triple antibiotic ointment. If not better in a week or so you will have to be seen by a doc/ Urologist for proper diagnosis and care