"How do I find forms 8996 and 8997 for investment in Qualified Opportunity Funds?"

Those forms are not supported in any of the TT programs ... if you need them you have to do them by hand and then use the FORMS mode in a downloaded program to enter the information on the proper forms. Efiling will not be possible ... those forms must be included with the return you paper file. 

This may be a year for you to use a local tax pro or upgrade to the TT LIVE FULL SERVICE option.

It's a shame really that Turbo Tax doesn't have such a simple form, and doesn't support QOZ investments at all, for that matter.  I feel that after one has used the software loyally for over 20 years, the advice should not be "perhaps now is the time to start paying someone else to do your taxes".