Hey @Grace Kim, welcome to BP! Glad you're getting started, you're in the same boat as a lot of people here.
I am a multifamily syndicator and the partnerships vary based on each and every deal. On a 200+ property it may be necessary to bring on 4-5 General Partners for money raising, management, signing on the loan, etc. In this case a new LLC is formed for the property and for the management team, but that happens once we're moving through due diligence towards closing. On a smaller deal, all that may not be necessary as it could just be 1 GP.
You've likely thought through a lot already if you're considering creating an LLC, but I'd say it's important to consider what your overall strategy is. Are you looking to be an active investor in a general partnership on an apartment deal? If so, you might want to create a "Investment LLC" that becomes a part of future GPs. In this case, I'd say you don't have to form the LLC and pay to do so until you have a partnership and a property lined up/under contract. Then you can turn it on in a day or so.
If you're looking to be a passive investor, you may not need an LLC as the property and managing LLCs remove you from liability, but I'd definitely consult an attorney and/or CPA here. Again here, I'd say wait until you've vetted a syndicator and they have a property under contract and ready to go until you form the LLC.
You're definitely in the right place to ask all your questions and hopefully the above is helpful!