I can’t finish my 2020 return b/c every time I open and update it says the IRS is still working on it and will be ready soon. When?

Depends on the form.  If you took a disaster distribution in 2017 or 2018, you need for 8915-B.  That form will not be ready until 3/25. Click here for a link to Federal Form Availability.  If you are working on a Covid distribution, you will need to delete the 1099R then re-enter to get the Covid distribution screens.  

The American Rescue Plan was signed into law on March 11. This will include a third stimulus package. If you had issues receiving your earlier stimulus, then the best way to ensure that you are one of the first to receive future stimulus payments is to file your 2020 tax return as early as possible and use direct deposit so that the IRS will have your updated information. 
 
You can find the most up to date information from the IRS here, and read more from TurboTax here.