We have tenant that is stating they will start looking for another place to live.

You could let her know that you are too small to make reasonable accomodation if the stairs become an issue, but probably not worth it.As far as rent to income ratio, this is something you should set before you start taking applications, then stick to your standards. 

Figuring out where to start is hard sometimes. 

Hi - I’m relatively new to the real estate game and am just starting to read multiple books involving this topic.I noticed a house being cleaned up two weeks ago, talked to maintenance people, and was in the right place at the right time to talk to the owner.

It is important before you start and get to far that you have an aim point...  

I thought this would be the best way to make my dream come true.Congratulations, Sounds like you are off to a great start as a family!

Hi Dan, Refinancing at a lower LTV will make your monthly expense lower which helps your monthly cashflow but will also help you to secure a lower interest rate so that could be a good starting point for you. 

But there are so many nuances to that topic I can't even start to delve into it here.Your 2-4 unit theory will be tough.  

Side note, I'm on my way to get my Real Estate License, just passed the exam and starting the interview process with different companies hoping to find the right one .

Might be a good place to start!