HOA rules, HOA fees, and general mismanagement are three of many reasons I would stay away. 

The most popular post I ever wrote in these forums was three words long and all caps in response to the age-old question of what I would do if I suddenly had a million bucks.

We've been renting it out, splitting the disbursements three ways for a year.

Three validating responses...I'm 99% there!

Then, the first day the Tenant is Late and gives you an Excuse, you run over to put up the Three Day Notice on their Door or if possible give them Personal Service.

Ask three different investors, and you may get three different responses.

If anybody is doing all three, please share how do you run your business?

Well, three weeks after they move out, I have my contractor do some work on the bathroom and he needs access to the attic.

@Milton Carrillo changing the building from a two family to a three family would be considered a “change of use” which would trigger new construction standards, which are sprinklers.

Work with some qualified professional, i.e. attorney for starters, to help figure out how to structure this partnership.This all being said, figure out if your ~$40k now is sufficient to do anything.