What is the best way I should go about finding a duplex, triplex, or 4-plex?

Some work I would need done would be some tile replacement in a bathroom shower, a leaky sink faucet replaced, and kitchen fan replaced / fixed, and possibly (I am undecided here, depends on how much the previously-listed runs for cost) some framing done - My property was originally built as a single-family home and split into a duplex, but shutting off / sealing off a door, which is still a door.

@Jeremy M. this is plaster and I didn't check the walls at all, but I expect to find some there.

We've always purchased turn-key properties and are now thinking of buying a true fixer-upper at a lower cost and renovating (i.e. adding higher, architecturally interesting ceiling, ripping out walls, and designing a modern space, etc.). 

Needless to say, the walls didn’t come out flush.

Am in escrow on a duplex set to close in 2 weeks and went into contract on 2 SFR this afternoon.

This duplex was a whopping $475,000.

If you need any connections to contractors, insurance agents, title companies, appraisers, deals (off-market single families, duplexes, fully renovated turnkey properties, multifamily properties, buy and hold deals etc I have several deals that come across my desk each day), recourse and/or non-recourse lenders, my opinion on potential properties you are analyzing to buy etc I am more than happy to help you. 

Taking on $50K in credit card debt to go through a guru course isn't the same thing as a 30 year fixed rate mortgage of $100K on an income producing (hopefully, anyway) duplex. 

Prior to placing the building in service, M pays amounts to repair cement steps, refinish wood floors, patch holes in walls, and paint the interiors and exteriors of the building.