So pick a market that is easily and readily accessible to you.

When you are new as an investor, you also don't want to work with a new agent (you).Overall, I think a RE license is good for access (to homes to get reps and to the MLS) and I think the course itself is way more valuable for investors than agents (most just stay in residential and don't need to use all the weird stuff you learn).

The challenge with using a paid option is expecting one person to have all the knowledge you need to succeed unless that person is giving you access to their board. 

Unfortunately, Texas has a law prohibiting HELOCs on rental properties and I believe they also have a 70-75% max total loans allowed on the property which cuts into the equity I've built and would only allow for me to access 30K which would make it less appealing to go through the process for only 30K.

This market is not always available in the MLS, so making it more difficult.A commercial lending is possible even with SFH, that will depend on your lender and the access to commercial programs, it will all depend on the situation.  

Additional things to consider: where is the breaker box and do both units have access to it if needed?

Access to Larger Loan Amounts: Cross collateralization allows borrowers to leverage multiple properties, which can lead to a higher overall loan amount than what might be possible with a single property.2.

Do you use anything for remote access for maintenance? 

You may have to sell the whole property to access the funds in the IRA or 401k when you retire and for required minimum distributions. 

Pretty solid points here, I would also like to add refinancing with a non-traditional DSCR based loan can assist with getting access to cash quickly as there are many lenders that have a lower seasoning requirement.