My penis is red and itchy

Balanitis...: The most common cause of a red itchy penis, especially involving the glans (top) is something called is something called Balanitis, which is usually a fungal infection & easily treatable. It should be evaluated, could be done as a HealthTap consult, through your PCP or an urgent care. OTC medications usually don't work & prescription meds are usually required. There are other causes, but are rare.