There are risky, but high return options like QQQ which grew 27% over the last year or on the other side / safe end, there are super secure short term US government bonds like SGOV which pays out about 4.5% in dividends. 

The first thing I ask is why am I Buying the property.I always look at the exit strategy first, is it going to be a rental, a lease option sell, am I planning on living in it.

Ensure you collect a proper security deposit (typically one month's rent in Florida) to cover potential damages.Your plan to increase rent next year makes sense given rising costs (taxes, insurance, and maintenance).

If they do, your best bet is a local community bank that funds these types of properties.Another option is a private lender but that money will be pretty expensive, as mentioned 10%  + 

Refrigerators aren’t typically expected in Texas single-family rentals, and it may be the same in Georgia.For other appliances, buying new is usually the better choice.

I recommend that you find a trusted or recommended Mortgage Loan Originator (MLO), who can give you options for property-based loans (mostly investment loans) and they don't use your taxes but the P&L of the property.

Third, the typical person renting a room is not a home buyer candidate. 

The previous owner claims they never had the titles to these trailers, so that is not option. 

They do offer access to mutual funds, but I do not love this option.

But I think the better option is tenant pay for it, that way they will know it may go against them for not paying rent..