The primary challenge was ensuring the property met all zoning requirements for residential use after being a commercial space.

Start with your primary residence if you are currently renting.You can buy a duplex with only 3.5% FHA Loan and rent out the other side while you continue to learn about real estate investing.

We have >$2m in debt spread across the investment properties and our primary residence.

If my primary residence has $500k HELOC, could I use it to purchase a 2nd primary residence and rent out the first one?

See if you can get a copy of The Millionnaire Real Estate Investor by Keller.The Slight Edge and Atomic Habits too.Awesome board with many smart people having own suggestions and ideas to grow wealth!!

Buy and occupy for 2-3 years, improve it, and sell it tax free (up to $500k if you and your partner both OO for 2 yrs) so you can move onto the next one.Starting to think team house hacking might be the primary way for folks to make this model work nowadays.

From my observation/experience, Berryessa and Piedmont Hills areas are more family-oriented, so the demand there is generally for primary residences, renters, or travelers visiting families.

Do you have over $200k in equity in your primary home?

You can buy a single family home, live in it for a year, then rent it out afterwards, and that would effectively be an investment property after you moved out, but you also got the more beneficial terms of it being a primary residence loan.You could buy a single family home and rent out bedrooms while you are living there, and that would effectively be an investment property, but again, you have the more beneficial terms of a primary residence loan.I wouldn't get caught up so much on if a property you buy is an investment immediately so much as I would focus on what your goals are and how each purchase would be step towards your goals, whether that is house hacking or just buying investment properties you don't live in. 

Looking to sell my primary residence soon and will have approx. $150k in equity after closing costs, etc.