Ideally, I'd put more towards my principle faster if I have the cash.- Once I get 20% equity in the property, use another FHA loan to buy and live in another multi-family property then rent out both sides of my first duplex leading that to positive cash flow.- Repeat..Am I on the right track? 

I agree with Don that acquiring an interest in property without a title policy is short sighted. 

This is the portion of your payments that is applied to reducing the principle on the loan versus paid to the lender in interest.

Do you use any other data sights that might help determining accurate numbers? 

Congratulations on pursuing your Electrical Engineering degree and setting your sights on an exciting goal right after graduation!

I flew out there and did drive around the neighborhoods - they look much different in person than in photos and video tours (I do know a few CA investors who buy sight unseen in multiple states but I think their risk tolerance is higher than mine).   

Assets identified in this study include:Building systems: water heater, electrical distribution, HVAC, plumbinPermanent Fixtures: windows, doors, bathroom fixturesStructural Components: Roof construction, drywall, wood framingInterior Construction: Wood flooring, stairs, ceramic tileThis engineering-based cost segregation study included the following methodology:Physical Inspection through a site visitDocumentation review including architectural plans, accounting records and construction documentsA cost analysis which utilizes engineering principles in order to allocate costs to their applicable asset classificationsCalculation of the depreciation schedule using MACRSAs a reminder, bonus depreciation started to phase out in 2023.

Use the profit ONLY to pay off debt, and keep investing the principle. 

@Drago Stanimirovic thank you, and you are right I will probably do cost segregation studies at some point, but so far I have still been able to get to a loss on my taxes using the straight line 27.5 year depreciation schedules, I will probably do the cost segregation studies once I can't show a loss anymore, which will happen at some point as the rents increase and the amortization schedules shift to more principle and less interest.

I agree with your buying advice and those principles are still true today.