I just had my umbilicus pierced and now have a red rash and the site is quite tender. I am 22. What should I do?

From your brief history, it looks like you have an infection after piercing. It seems that the infection is moderately severe. 

The safest remedy is to get the ring out of the umbilicus and see a doctor. The longer the ring remains, the longer the infection will fester. You may also need antibiotics and hence a visit to a doctor is recommended. 

Just wiping with warm water or peroxide usually is not the way to treat an infection from a pierced ring. If you are not sure about the severity of your skin condition, go see a doctor as soon as possible. 

These infections can spread rapidly and be quite serious.