Thanks @Walter Bowser - I appreciate that advice and plan to incorporate it into this first opportunity and beyond. 

I'm not sure what AZ has incentive wise but in Los Angeles because there's a housing shortage there are some incentives that you can take advantage of like...CalHFA ADU Grant ProgramThe California Housing Finance Agency (CalHFA) offers grants up to $40,000 to cover pre-development costs such as architectural plans, permits, and utility connections.

After we solidify their investment strategy and timeline, I connect them with my network (lenders, agents, other investors) to get them pre-appproved and out submitting offers!!

Tenants in the room rental space can be challenging, need to pre-vet and develop personal relationships Did you work with any real estate professionals (agents, lenders, etc.) that you'd recommend to others?

A lender who gave us a pre-approval says with my income level, it is not wise to buy an investment property before a primary residence, as the lender on my future primary home will count only half the rental income and the whole investment mortgage in my DTI calculation.  

We chose a different GC because the engineer team was taking far too long to finalize the plans and ended up providing a bid well above market.We finished fundraising and launched pre-sales.

Congrats Philip on being pre-approved and joining the BiggerPockets world.

Get contractors names of houses you think look very nice.Once you think you have a good handle on the kind of money that is needed, do a credit check and make sure you are 700+.If you are a 0 experience, it will be hard to get a general pre approval. 

The Pre-Approval letter is worthless if it is not coming from a trusted source.

What I'm trying to figure out is if the cost to repair the current structure (my amateur estimate is between $750 and $1M) is more or the same as demolishing the structure and re-building (including installing a pre-fab) from the ground up.Appreciate other's perspectives!