Can start filing for 2020? without visiting Form 1099-R Retirement, because I am not retired.

The TurboTax online editions are only for tax year 2023.

 

If you file a 2020 tax return with a tax refund, the refund will not be paid since it is beyond the 3 years from the due date of the original tax return.

 

To complete and file a 2020 tax return using TurboTax you would need to purchase, download and install on a personal computer one of the 2020desktop editions from this website - https://turbotax.intuit.com/personal-taxes/past-years-products/

 

A 2020 tax return can only be printed and mailed, it cannot be e-filed using TurboTax.

You mentioned "file my 2020 taxes over".  To correct a tax return that has been filed and accepted by the IRS you will need to amend the tax return.

 

See this TurboTax support FAQ for amending a prior year tax return - https://ttlc.intuit.com/turbotax-support/en-us/help-article/tax-return/amend-change-correct-return-already-filed/L4VjJ9BA2_US_en_US?uid=ld1n99kr