What forms do i print, sign and mail and after i amend my taxes?

In the FILE tab step 2 choose to mail in the amended return THEN  go to the PRINT CENTER under the TOOLS bar  and the mailing instructions will be included in the PDF.  You will send the 1040X (not the 1040) plus any other forms & schedules that changed and attach any new forms added that had withholding on them.  

what year? 2019 and prior must be mailed. however, a 2020 amended return may be e-filed which does not require a signature.  do save a pdf copy.  

2020… I seen I didn’t have to mail anything for the federal but for the state I’m a bit confused.

For 2020 I know I don’t need to mail anything but what about the state amendment? I live in GA.

visit your state revenue dept website and refer to the instructions for how to assemble and file an amended tax return.