I found someone who just graduated from college and said that she doesn't have the best credit because of some credit card mistakes she made in college.

I'm trying to determine what a bank or credit union will give me.

Credit score is in the low 700sI'm looking for a new primary and would like to use this as a rental. 

Assuming you have good income/debt and good credit, you should be able to get another mortgage.

I currently bank with a credit union, is that a good option to apply for a mortgage loan or should I branch out?

But he has crappy credit so he can't do it for a year. 

So if your car payment, student loans, credit cards, current mortgage all add up to $500 (wouldn't that be nice!)

Yes, build some credit.

Walmart sells window units for 119$ is your tenant that poor they can’t just buy one or find one on Craigslist for 40 bucks?

(I've tried two property managers, but have fired both because of poor performance...I have one for my out of town property & he is amazing)Option 2) Use commercial bank financing through my local bank to continue making acquisitions of SFRs to grow the portfolio.