Suggest Cure For Infection On The Penis

Hi I Had gone swimming in a friends Pool yesterday and at night when i came back the skin around my genitals was red and irritated just really the skin on top of the penis was red. But Its sometimes very itchy and I tried to use Moisturizer Cream to relieve the itch and I thought maybe it is dry skin but I am unsure. Could You help me find out what is causing it and how I can treat it? Thank You