What happens if I live on another state now and my w-2 has my old address?

Nothing. The address on your W-2 is not important. Only the address you enter in the mailing address section in the MY INFO section matters. Just enter the W-2 exactly as printed.

The address on your W-2 does not affect your ability to enter it on your tax return.  People move all the time.  Make sure you use the correct address on your tax return so you can get mail from the IRS.