What does it mean when the urethra right under my penis itches and there is a light white cloudy discharge?

See a doctor: This may be a sexually transmitted disease, or a urinary tract infection. Either way it will require a history, exam and possibly some labs. If an std you should be tested for others.

Discharge: Sounds like urethritis. Urethral discharge is not good. Could be a sti like chlamydia or gonorrhea, could be irritation, could be a fungal infection, could be lichens sclerosis. Hard to say without seeing it. Best to have it evaluated.