If I forgot to file my 1099-G and a W-2 when will I be able to amend my return? Also how will it affect my return?

[AnnetteB6]

The forms required for amending your 2020 tax return should be ready in TurboTax now.  You have up to three years from the due date of your return to amend it to include income that you previously left off.

Without knowing more about the tax return that you originally filed and the W-2 you are adding, there is no way to predict whether you will receive an additional refund or be required to pay some money back to the IRS.  The unemployment reported on Form 1099-G will need to be entered, but it will not be taxable up to $10,200.  Any Federal income tax withholdings will be taken into account on your return and will most likely be refunded to you.  

Take a look at the following TurboTax article for instructions to amend:  How do I amend my 2020 return?