Leveraging an owner occupied loan, putting as little as 5% down with a conventional mortgage (I have lenders that will offer NO pmi as well) and buying a multi family will fast track your REI journey. 

https://www.amazon.com/Building-Occupying-Selling-Homes-Lega...

I would like to plan my start for scaling (thinking of starting out with an owner occupied 2+ units to give a bit of experience owning and being a landlord.

This was my first tenant occupied visit and my second ever property visit. 

For example in many jurisdictions I can STR units in a duplex but cannot STR an ADU (some jurisdictions will let you STR if you owner occupy).

I'm unsure what the right path is, but I've been reading about investing in owner-occupied, multi-family properties.

Generally, SBA loans can only be used directly for real estate purchases if the loan is being used to purchase a facility for a non-real estate investment business that will owner-occupy at least 51% of the property.

However, keep in mind, you will have to notify your insurance company that the property is no longer owner occupied but rather a rental. 

The surrounding neighborhoods (West Passyunk, Girard Estates) currently have pretty strong fundamentals, although weigh towards owner-occupied.

If it's an owner occupied unit sometimes I've found the big players like state farm to be pretty competitive on price.