I don't truly understand the capital needed to start the REI process or if I shoukd be paying off debt or what first..

One year we discovered that mice were in our "private" closet, eating boxed and bagged food, while nesting in some towels. 

Drinks & food on me 👍🏾

It's been a lifelong goal of mine to have land to keep as many cars on as I want, to build a homestead, grow food (ie permaculture), etc.

But then you need to find food management which may be the more difficult thing to find of the two.I have not had as difficult of a time finding properties as you have described but that is probably because of the market I am in, the people I have partnered with, and the connections I have made over the past 4 years or so.I would suggest finding a mentor, bringing value, and then doing what your shows you to do.Good Luck.

Cleaning out units, I plan to pay a cleaning company for turnover and pass on any extra fees for cleaning out units (like left furniture/food etc.) onto the tenants via a deduction in security deposit. 

Its a business I run...It puts food on the table for my family.  

I have some experience, having knocked down a drive through location and replaced it with a national food service company in a nice town and then also purchasing a historic bank building and leasing it out as office space. 

It is never a fast process or it shouldn't be. 

Some REIA meetings might also have food if hosted out of a restaurant space.You can find some free ones with Meetup.com, but they aren't completely free because Meetup charges the host of the Meetup group monthly fees.