It is possible that you will owe something when you add some income--we cannot see your information so cannot predict. You will need to amend to add the W-2.
Do not try to change anything on your return now. When you amend, your Form 1040X has to be prepared from the return exactly the way it looked when you filed it originally. You have to wait. Once your return has been processed you will complete a Form 1040X --- which is not yet available --- and submit it to amend the mistakes made when you filed your original return. It takes the IRS at least four months to process an amended return.
The Form 1040X you need is under revision and is not ready yet. The Form 1040X does not become available in the software until the end of March 2021 (subject to change).
https://www.irs.gov/forms-pubs/new-information-for-form-1040-x-filers
**Disclaimer: Every effort has been made to offer the most correct information possible. The poster disclaims any legal responsibility for the accuracy of the information that is contained in this post.**
