@Roston ElwellSection 121 is the code section that allows you to exclude $250,000/$500,000 of the capital gain on the sale of a personal residence depending on if your filing status.Section 121 requires you to live and own the residence to take advantage of the exclusion.You will satisfy the requirement of living in the house.

It all depends on the numbers though.

Depending on taxable income of the LLC, your dad's other taxable income, projected growth of the business, and your dad's goals for the business, an election to have the LLC taxed as an S Corp or a C Corp might make sense now or in the future. 

That's a decision only you can make, depending on how much risk you're willing to accept, how much risk you're willing to buy down, and how much you're willing to pay for it.There is no "One Size Fits All".Also, it kinda depends on what the numbers are.

Depending on your goal and strategy you can flip or BRRRR an apartment complex, the same way you would a SFH (over a longer period of course) and make a fantastic return.

For my 2 cents - depending on the size of the market you want to mail to, I'd do both. 

@Parris Edwards depends what type of deal your underwriting.

It all depends on your goals, capital available to you, and the amount of time you have to dedicate to this.  

Depends on state law and your lease.

If it's not in your name, it's not your responsibility.Now, you two get married, then that's a completely different picture, depending on how your jurisdiction handles community property.In any event, I'd suggest you find a local lender and get pre-qualified.