Much of what you can learn (Marketing, local law, fair housing) is going to carry over quite a bit to the investing side of your business. 

I will be doing most if not all the rehab with my soon to be father In law.

I am an attorney working in criminal litigation, prosecution, but I also have experience with landlord tenant law and real estate law.  

Isn't that against the law.

Other license laws state that the type has to be a size the same or larger than the agents contact information.

Regulations stipulate to get an LLC to hold the company, but the law doesnt require that the holdings company be registered with the state in which it originates.

They will also have all the paperwork and local laws figured out.

In my day job, I am a corporate and securities lawyer and I frequently help real estate developers structure the legal entities they utilize for the investments and also comply with federal and state securities laws in connection with bringing on investors.  

The property also has a second structure, the in-law suite, which was probably a garage that a previous owner had converted to a 2/1.

A 'pay or quit' or 'pay or vacate' is a 3-7 day (depending on your state law) notice to the tenants to pay the amount owed or vacate.