Read and understood your concerns.
Red bumps on penis after sex for the first time can be due to a condition called Balanoposthitis.
This needs a treatment of both of you with antibiotics and metronidazole.
Proper personal hygiene is also needed.
Take care and get your partner checked by a Gynecologist.
Hope this helps you.
These Q&A’s are for educational purposes and should not be relied upon as a substitute for medical advice you may receive from your physician. If you have a medical emergency, please call 911. These answers do not constitute or initiate a patient/doctor relationship.