If anything, I could maybe picture an independent bank willing to collateralize a stabilized syndicated investment that already had a long history of consistent payment.

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

You need property valued greater than $480000; a live person with ID and proof they own 51% of the fund to sign; property has to cash flow DSCR; credit history... to name a few items

One thing i did notice was that he didn't have a rental history (red flag i guess) but when i asked he said he leaved in another city with family and has never had the need to rent.September and October rents were paid on time but after that from October to February his rent payment was a hassle to get as we had to call till they were finally paid.Then came the Covid-19, we tried to worked something out.

Compare that to the property manager projections for the same property.I wouldn’t put much stock in what the owner says or really in rental history at all.

Because of this, my work history is sporadic and in several different fields—making it difficult to get a conventional first-time homebuyers loan.I’ve tried looking at properties in the past, but it’s felt like agents don’t take me seriously because I’m not pre-approved and I’m so young.

They give funds to local housing authorities to distribute as vouchers for individual tenants. 

I imagine given history this should be easier (but I am in the dark on this one). 

Go to Freddie and Fannie website and get the list of authorized direct lenders. https://mf.freddiemac.com/smal...https://multifamily.fanniemae....

Honestly, the key document you would need is a solid operating agreement where you clearly define the articles (books,records and accounting, capital contributions, signatory authority, distributions etc.).