Run a thorough background check, make sure they have the financial ability to pay their rent, and then you can use social media to help you make an informed decision.

I will be working towards changing mine and any helpful advice or resources would be greatly appreciated.

The best approach is to source a few HML resources in your area and talk to them about their programs and guidelines.

They are expensive, but a good resource and can usually close quickly (which can be a necessity with many deals).  

I have a passion for helping other people achieve financial freedom so they can fully live their purpose, instead of being limited by resources.  

Have you considered selling the 19 units to scale up to 48 units freeing up bandwidth, resources and capital?

If you have a well-maintained unit in a decent area, your tenants will want to stay, even if the increase is substantial and it is within market rent.BTW, prior to purchasing, ask the owner for copies of the most recent utility bills, tenant estoppel certificates (signed paper from tenant stating financial terms of the lease) and CLUE report ( A report that lists if any insurance claims have been filed against the property in the last 7 years) to ensure property is insurable.

My husband has been reading a lot about financial "freedom" and one topic that got his eye was Real Estate Investing.  

Check out the "Books and Resources" tab under "Education." 

I just got financial information and since Jan 2016 the income is up and down several times.