@Michael Lightwood I believe the best way to get started is by purchasing a house hack in which you rent out rooms to cover the mortgage or rent out a side or two of a duplex/triplex, using a primary residence loan 3-5% down conventional.

On the other hand, you can use conventional financing on the duplexes. 

Conventional FNMA or FHMLC is maxed at 75% for an investment property.

I am doing a 30 year conventional.  

The home had a conventional offer submitted the day we saw it and my realtor, convinced this was the best home on the market for the purposes of getting the FHA loan approved, proposed a strategy that involved an above-asking offer to ensure we had an accepted offer.

We were able to get a home that needed a good bit of repairs with a conventional loan, and they gained a ton of equity in it.

Conventional 30-year thru local bank

If you have no income you cannot close with a conventional lowest rate loan.

Would it be a good idea to still write an offer with Seller Financing in addition to a more conventional offer?

You can purchase a single family home with an ADU with 3.5% down payment using FHA loan or 5% down using a conventional loan or you can purchase a duplex with 3.5% down.