It's best to start with a 300 unit complex.

Discipline of registering expenses as they occur.There are other software suites that charge and have more complexity. 

I am interested in the BRRRR strategy, but I am locked into a 1 year lease in my apartment complex starting in August, and I would love to start the process before then if at all possible. 

Secondly,there is nothing very complex about what you are proposing but rather than books or courses, what you need is to hire a competent attorney.

Big complexes/companies won't tell you anything over the phone so I usually just drive to the complex with a form and the signed authorization to get rental information and the PM will just fill it out for me. 

Properties are occupied by people who have lived in them for a long time and have no intention of selling and not much area to do new construction of apartment complexes which is a lot of bread that I don’t have.

I would like to dive more into multifamily complexes. 

What I need help with is evaluating the property with regards to future expenditures - capital or otherwise and forced value.I have no experience in evaluating a house let alone an apartment complex. 

I assume I need to run the numbers for my area on multi families to see if that 15k would even touch a down payment amount suitable for a reasonable starting complex.

Two to four apartment complexes.