They could come in the form of business lines of credit, credit card stacking, short term & receivables based financing. 

The only thing I can pay off is a credit card which is a tiny $90 monthly payment.  

He will most likely need to file bankruptcy here in the near future (credit cards) while she is on Social Security Disability so her ability to support herself is very limited.

Are you expected to have 10 separate Credit Cards, one for each property?

First thing I suggest you do (today) is get a secured credit card.

I was browsing the Real Estate Investing books when I ran across a book that had a card sticking out like a bookmark. 

( I’ve had good luck playing that card showing the owner the cost get the complex in compliance or buying contingent on it being compliant)-expenses seem a little light if it really is a somewhat run down property in a bad area ( depending on your investment strategy these properties tend provide better cash flow to somewhat compensate for the lack in appreciation)-are tenants paying utilities?

But, fi something happens, all the cards will come down.

It is like a credit card but attached to your property so the interest rate is not super high.

What I would start doing now ,while you are in school and putting money aside for a down payment,  is to get yourself one credit card.