The AC is old, but I’m planning on holding off on replacing it.

Check on VRBO and Airbnb.

In that process, I got my real estate license to buy the house and save on fees. 

Or are you planning to put 100% of the risk/cost of vacancies, furnishings and tenant nonpayment on the owner with you having 0% risk?

And you would get to indefinitely defer all tax on the gain from the sale.

@Chanel Snerling not sure why you are so focused on building?

While you are at it, put the next person on MTM to create some equity in the contract when you have problem in the future.

Both of our properties have about 100k in equity in them so we were thinking about using getting a HELOC on the duplex rental property and use that money for the down payment on the next property.

Example of what a tenant might say - this 2x2' stain on 2 year old carpet was already there when I moved in.  

Did you inherit this home with a step up in tax basis or will you need to pay taxes on any gains if you sell?