You will have to wait until your employer issues the W-2. Employers have until February 1, 2021 to give you the 2020 W-2.
The IRS will not be accepting any type of 2020 tax return until January 27, 2021 so there is no need to rush your tax return. E-filing of the 2020 tax return will not be available until early January 2021.
The finalized IRS Form 1040 will not be available until January 7, 2021 (subject to change)
