Some have informed me that I must officially receive the keys and obtain evidence of the tenant's formal surrender of the property.

Unlike a formal educational program, there was ZERO structure and ZERO standards.  

For anyone who may end up reading this, as a follow up, (1) auction.com ended up not requiring the full $2500 deposit, since my purchase was less than the deposit requirement. (2) It took about 2 months to get the deed, because CHASE had a pre-foreclosure on it at the time of the auction, and so they formally foreclosed and then eventually got the deed, which they then eventually signed over to me. 

Meanwhile,  the real estate agent pushed “off market” properties are typically off market because they can’t convince the owner to sign an exclusive agency listing agreement and instead convince the seller to allow them to market the property without a formal agreement.

Formalize agreements to avoid future misunderstandings and ensure everyone is on the same page.

Yes, failure to observe corporate formalities can lead to piercing the corporate veil, but if it was only obeying you, then you can be sued in your own right, in addition to the corporate entity.Then there’s the question of umbrella insurance.

You may have to do a formal eviction.The seller will not tell you anything about the status of the occupant. 

I don't personally think you need a formal mentor, I would recommend simply asking questions constantly to anyone in the industry you encounter, and with time you will formulate an appropriate plan and goals for yourself.

I don't have a formal business set up yet or an LLC.... just operating as a sole prop. 

Even if the change in ownership is merely a formality and effectively I'm still the only owner?