What would you need to increase 15 amps to 30 amps?

If you're trying to increase the capacity of an outlet from 15 amps to 30 amps, start with the wiring.

A 15 amp circuit typically uses 14 AWG wire, it's a lot smaller in diameter than the 10 AWG wire necessary for a 30 amp circuit. Failure to use 10 AWG wire on a 30 amp circuit will result in a serious risk of fire.

ONLY AFTER you've replaced the wire, then can you replace the outlet and the circuit breaker.

Since you obviously have not done this before, contact a qualified electrician to perform that work for you. Any money that you might think you are saving by attempting to do this work yourself will not be worth the risk to your home and the people who live in it.

Electricity is a valuable tool, but it is also unforgiving. It can kill you in an instant or cause a fire that destroys everything that you have.