Interesting book recommendation: Whack-A-Mole: The Price We Pay for Expecting Perfection by David Marx.

I have heard of lenders that do HELOCs on investments but I would recommend just doing a cash out refinance.

Any company recommendations? 

No need for any overpriced education, just read books on real estate investing during your down time (I would recommend the "ABCs or Real Estate Investing" by Ken Mcelroy if you are brand new) and listen to the BP podcast when you're commuting, cleaning, cooking, etc.

Would you recommend any resources for exploring corporate housing? 

I’ve got several great property management recommendations in the area.

Hi John, I recommend reaching out to a local property manager (search on Google Maps) with many 5-star reviews to see what legal action you can take before the Sheriff is available to execute the eviction.Property managers specialize in landlord-tenant law and should be able to help you determine a path forward that doesn't require waiting 3 months after the lease ends.

I highly recommend that you read The ABCs of Real Estate Investing by Ken McElroy.

Which calculator do you recommend that I use?

At this point, I would recommend having a line of credit to cover these things so you don't have money sitting in the bank doing nothing when it could be put to work.I have 33 units, no debt except for mortgages, and excellent income.