This is normal.
You need to stretch the foreskin. Skin grows by stretching. Using your fingers you can spread the opening OR another method is to get an erection and pull down on the shaft skin.
You can do it in the shower if you want.
The more often you do this the faster the results. Don't hurt yourself, just stretch it as you feel comfortable. Some discomfort is normal. Never force the foreskin back, it can get stuck. Wait until it's stretched enough.
You'll find the head to be very sensitive as well, it's normal.
Check this thread:
Hope it helps.