He outlines what essentially amounts to a BRRRR but with the caveat that the property is owned by his LLC and then sold to his wife.

Buying cheap on the outline of a major city is completely different the buying up a city that has never really been alive Best of luck brother dig deep and get CREATIVE!

Here is the first result from Google for "20 unit apartment building plans" https://www.togal.ai/blog/20-unit-apartment-building-plansAny plan you pull off the internet will still need, likely, thousands of dollars of architectural work to meet your local building code.Beyond the plans, which don't outline any finishes, you can swing a budget 50%+ if you went high end finishes versus low end.  

Also, is there some sort of special agreement that need to be set up with the property outlining how each owner should split exterior maintenance?

I'll outline some strategies here:1) Education - Books - read the best books on the subject but also these books (Deep Work; and Essentialism).  

Its a legal entity protection wise and you can outline the details in the operating agreement.

It outlined the responsibilities for each person, the return structure, etc. 

Make sure your agent can give you a full outline of benefits and gaps before you settle for cheap or pay to much.  

Thank you for outlining your journey here as well!

The funding package should include a executive summary outlining what, how much capital, and how will pay back the loan, copy of the signed contract, a copy of your tri-merge credit profile (they will pull one from their credit vendor regardless), a personal financial statement (may not ask but helps to have it), and bank statement showing the necessary equity liquidity.