What does it mean for a 16 yr old boy to have pain and bleeding from his penis during urination?

Several things: It is not normal, first. Second, what are the symptoms other than pain and blood. Fever? Trauma? Flank pain? History of kidney stones? Are you having lower abdominal cramping? This is a very worrisome complaint. You should be seen right away.

Additionally...: It can also be related to infections, sexually transmitted diseases, growths in the urethra, and trauma from sex or masturbation.

Blood in urine: Likely infection given age but needs full urologic evaluation.