My long-term goal is to own 20 units, and I’m trying to figure out the best strategy to keep growing.Current SituationI've been using my primary residence’s HELOC to finance and renovate my rental properties.

As others have noted above, you could easily get overwhelmed if you try to self-manage.

The worst part is, during 4+ years of problems, I’ve continuously tried to give them the benefit of the doubt and hoped they would learn from their mistakes.

I am brand new to real estate and am trying to start wholesaling, I have a realtor that I am working with to find homes.

I would try to work with investor friendly real estate agents.

My university had resources for parents and alumni which included where to stay and info about the local area so you can try connecting directly with the school.

I'm still trying to understand your thoughts around putting money in escrow. 

Over the years, I've built up decent cushion in stocks and retirement accounts - I'm right now trying to figure out where to get started... 

I'm trying to figure out ways to pull some cash out, so I can make more long term investments and keep some liquidity on hand, while still keeping my expenses low. 

Quote from @Edward Barrett: New investor here trying to stay in my local market (Dayton, OH).Since I've started looking for my first deal I've come across a few section 8 properties that seem to pencil, but I'm a bit loath to jump into that kind of deal.