@Adam Hurst A joint-venture agreement could be used for long term while an LLC is created per acquisition with splits relative to the resource or effort on each property.

My question is: what are avenues I can take to better prepare myself for my RE investing journey?

If that doesn't work I would prepare the damage myself and if it happens again get the HOA and owner of that other unit involved.

However, I will advise, that waiting until you individually have 20% will typically be better than rushing into a partnership without preparation.

The lender should have enough information to run a Term Sheet that describes the loan they will issue if everything checks out.Have the sellers prepare 3 years tax returns and P&Ls, plus YTD for 2021. 

What is the best way for me to prepare for selling the house "as-is"?

I have a SFH that has done well and my tenants (whom I really like)told me that the next-door neighbors are preparing to sell.

Any tips on preparing for the California Broker exam?

You will see unprepared landlords bemoaning the "tenant friendly" court and you will see prepared landlords getting what they seek.

It probably couldn't hurt to learn about it in the meantime to be prepared for a different market when things have changed but for now I wouldn't expect to find many deals in foreclosures.