I speak from painful and expensive experience.  

This rent covered all expenses on the 15 year mortgage, insurance, and HOA fees with small profit that got eaten up on paper by LLC expenses, depreciation, PM and accounting fees, etc.  

You cannot be taking that expense. 

I am very lucky because I have zero debt and no bills other than phone and food since I decided to get rid of my car I have no expenses now.

Analyzing income and expenses will give you an idea of what kind of free cash flows you can expect based on your invested dollars.Globally speaking, ROI's can range all over the place depending on so many factors (purchase price, terms of debt, occupancy, rehab efforts etc.).

You will have higher expenses.

Also, any CPA recommendations and/or tips on keeping track of expenses/documents?

Look in forums for HML - they are expensive and mostly for a year or less.  

With a HELOC, you have no extra expense (some HELOC has annual fees, but they are low - like $100 - $200 at most which is negligible) unless you actually pull the cash out.  

The market here is relatively expensive, we both have pretty good jobs, but would like to avoid using our entire savings to get this off the ground.