I'm thinking of getting a single family home, with a mother in law apartment with a separate entrance, living in the basement, but eventually renting it to two families as an unofficial duplex.

If you can create separate entrances to both spaces, then i would do that.  

They then added a deck with an exterior entrance that leads to the attic and built a separate driveway for that space.Currently, we rent out the attic space on Airbnb and more than pay for our mortgage.Other home features:-Granite counter tops-Custom cabinetry-Hardwood floors throughout-Crown molding throughout-Front porch, patio, and deck-8ft SOLID privacy fence enclosing a HUGE backyard-2 driveways-As of 2009-- all new electric, plumbing to the street, roof, and HVAC.

I'm wanting to house hack, but I have a little family, so I need my own space, and the multi-family in my area are too expensive to cash flow right now.I'm thinking of getting a single family home, with a mother in law apartment with a separate entrance, living in the basement, but eventually renting it to two families as an unofficial duplex.Are there any cons to this, other than paying by own utilities?

A lot of the events are "gurus" who put on an event for free and give you just a hint of information without giving any real "meat" to the discussion and then they pitch their low cost membership which gives you entrance to some class where they pitch a high price "Special group", and on and on and on.   

Can you get a separate entrance?

I've seen a few that had separate utilities and entrances but when I look at the public record it says SF.

HPU is surrounded by a 6-foot (or taller) iron fence and the only entrance is constantly manned by one or two guards in a guard booth. 

Each unit has its own separate entrance but the home has a two family CO and is only zoned for two family. 

Is the door  in question a common entrance?