If I am self managing my portfolio, what do I need to check/confirm, and what easily available tools are at my disposal (online, other) to help me do this? 

Both strategies have potential here, so it depends on your goals:Strategy 1 (Duplex) can be a solid choice for building equity and generating cash flow, especially in Austin’s competitive short-term rental market.

@Eric L ConryThis is a highly personal choice.

A property manager that can assist with rent collection, tenant screening, maintenance, and run an online ledger for us to track expenses.

.: As a contractor and flipper, I dont buy materials from retailers or online.

For what you are trying to achieve you'll want to stick to the suburbs and a few choice neighborhoods on the West Side of the city.

Best experience is hand on training, and not some workshop making you go back to pay for free information online. 

It’s not necessary to stay local for these services as long as you have online bank statements or a solid way to get them to the bookkeeper.

Vet anyone you get referred online heavily. 

Rehab contractor charged $10K, the online report says $16K.