To set up an llc file articles of organization with the state--usually a 1-2 page document--and pay a fee. Then pay an annual fee. The operating agreement (and bylaws) is the document that sets the rules of the llc (keep in your files only). If it is owned by just you and you will not have any employees (likely) then it will likely be a disregarded entity--no need to file a separate tax return or obtain an EIN.
Since you own the property already you will have to quit claim the property to the llc. If you have a loan the bank will have to approve it--some won't do it. Get an attorney until you understand the process (it is straightforward if you do it correctly but the cost to correct errors may not be)
The llc will protect your other assets if something occurs within the llc that you didn't personally do--slip and fall, etc. You still need insurance so the property itself is not at risk. It may be cheaper to get a large umbrella policy--depends on the state and costs. An llc can also make things more difficult--you will need an attorney to go to court for an llc but not if you own in your own name, etc.