My seller was supposed to fixed the main sewer as we found out leaks during inspection.

As state above, the main concern is doing your own numbers.  

Nick,Why can't you buy the house as a "rental" and then when you are not able to rent it out easily and then you can move into the main house and rent out the ADU. 

A fire pit, BBQ grill, or outdoor dining area can also be great selling points.Themed Decor: Consider a lake or nature-themed decor to enhance the experience.

The first floor features a renovated kitchen with a large island, connecting a cozy sitting room, a living room with a 55" TV, a dining area, and a spacious back porch.

I'd say first identify a strategy, choose a market that aligns with it and establish your Core 4 Real Estate Team.The main challenge I observed is that individuals often lack a clear end goal or strategy or they select a market that doesn't align with their chosen strategy.

We have been flipping houses mainly and started 1 1/2 years ago.We are up to house #15I recently bought our first multifamily -  3 family in West New York, NJ at a Sheriff forclosure auction.  

The first floor of this private home offers a bright renovated kitchen with a large island centrally located between a cozy sitting room, the living room with 55" TV, a dining area, and the spacious back porch.

The layout across the top of the image is garage, dining room, hall, closet, and two bedrooms.  

Mainly it was kind of a bonus to us since we sold for  significantly more then we valued the portfolio at, and without an agent.