@Jeremy Bohnett
Welcome to the BP forums! Fellow Issaquah resident here. Still getting started in REI, too, but been preparing for the last year, basically.
Regarding your questions:
1. Start your own LLC with just you and your partner. Keep it simple and clean. Messiness leads to liability.
2. The LLC that will be the legal owner of the property needs to be registered with the state in which the property resides. On a related note, if you dig into legal entity structures, you'll often see mention of having an "asset holding" LLC that then owns the LLCs that own the properties. This "asset holding" LLC is usually registered in states with favorable legal rules, such as Wyoming or Nevada. In my case, my asset holding LLC is in WY, and it in turn owns my WA LLC that will hold property/properties. I'll also add that you'll hear mixed opinions on whether all of this is necessary--that's for you to research and decide in the end. We chose to set it up from the start to reduce our legal exposure and not try to shoe-horn it in later, but it also costs more money to establish and maintain.
3. You and your partner will probably both provide a PFS to the bank/lender and be the guarantors of the loan, especially if you don't have a track record. As Basit mentioned, you can buy in your name and transfer to LLC, but that can also get weird with the Due On Sale clause (though unlikely). If you do that, I've always been told to be sure to use a warranty deed, not quick claim deed. There are other options, like land trusts, that can be used to avoid the DOS clause, but those will cost more.
Pete