I recommend discussing your concern with a urologist
. Males are born with foreskin that cover the head of the penis. Some males are circumcised at birth where they surgically remove the foreskin. It sounds like you still have your foreskin and you seem to have trouble retracting it. The foreskin covers the glans of the penis. Urine, semen, and skin cells can accumulate behind of the head of the penis which is called smegma. If it is not cleaned daily, it could cause worsening smegma which can cause really bad odors. If you cannot retract the foreskin, you may have a condition called phimosis. Again, you should make an appointment with a urologist to discuss the problems you are having. They can help you retract it or teach you stretching exercises to loosen the foreskin. You should not try to attempt it on your own right now because if you retract it and the foreskin gets trapped, you could have a condition called paraphimosis where the head of the penis gets swollen from the foreskin constricting the head of the penis. You can discuss with your doctor
about the surgical options as well, such as circumcision. At this point, it is unclear what treatment you need, but the first step is talking to a urologist.