- Should I get a real estate agent or realtor estate lawyer to help me with paperwork that because I have no clue when it comes down to contracts/documents regarding sales/purchases. 

What documents do they require, what credit scores do they allow, how do they verify previous rental history, etc.?

Document thoroughly.

(adding the layer of privacy) If the LLC is owned by the holding company, and you purchased these other properties in the name of the LLC, then all of the documentation should have been taken care of between the bank and the title company.

What documents do they require, what credit scores do they allow, how do they verify previous rental history, etc.?

If your intention is to use subject to, to enter into a business with another individual, the best advice is to have an attorney draw up both documents.

What documents do they require, what credit scores do they allow, how do they verify previous rental history, etc.?

If you are still not able to make it, you might have to go back and go through all your returns and property documents to figure out the cost. 

I'm going to have an attorney review my lease agreement, but all the documentation that I have came with my BiggerPockets MANAGING RENTAL PROPERTIES book a few years ago, pre-pandemic...and it's a lot.For those using KeyCheck for their MTR listings, did you also find that additional documentation was needed, besides the 3 key things that KC provides? 

With completed & documented rehab, no seasoning is available.