consult an attorney. I am in Nevada, we allow for LLC's and series LLC's, both are useful for real estate rentals. For most clients, you are fine with a single LLC that holds your rental business. Sure, you can do an LLC for each house, but you need to isolate them completely from each other to a degree that most people just wont do. The most important reason to have an LLC for your rentals is to separate them from your personal assets. That is a division that most people can actually stick to. There are also tax benefits to doing an LLC.

Some states allow for a series LLC, which is in effect an llc with internal divisions inside of it. Again, it require way more administration than you will probably need, and so I would just get a normal LLC. Generally you see series LLCs when a company owns multiple apartment complexes for example.

Get an attorney to set one up for you, they can draft you an operating agreement and remind you to renew it each year.