On step two under File, Your refund info the text states The IRS hasn't finalized one or more of my forms... How do I find out which form? and when can I expect this?

There are many forms and schedules which have not been finalized by the IRS.  In the Review section of the program the required forms and schedules for your federal tax return will be listed.

See this TurboTax support FAQ for IRS forms availability - https://care-cdn.prodsupportsite.a.intuit.com/forms-availability/turbotax_fed_online_individual.html

What year are you trying to file?  It is way too early to file 2020.  The year is not over yet.  And you have to wait until you get all your W2s and 1099 which might not come until the end of January.

And even if Turbo Tax starts taking efiles on Jan 7 the IRS won't open efile until Jan 27.  So they will just sit in storage at Turbo Tax.