A Verizon sales guy just came to our house trying to sell his service. After listening to his shpeel, I started complaining to him about how Verizon forces you to combine the WiFi and modem together into one device. I don’t like this because I want to have full control over what WiFi I have, with my own router.
At first he seemed confused. “We don’t use WiFi. It’s fiber!”
Next he started to sell it as a good thing “why worry about multiple devices when you could have just one?”
Finally he told me “ah you just want to waste my time”, shook my hand, and left.
No, you can’t. I agree that it’s annoying, but it not made for you or I.
If these are questions you don’t already have the answers to, though, you need to do some research before you commit to a self-managed LAN. Find out what modems are compatible with your ISP, the basics of pfSense/OpenSense, invest in a cheap machine to run one of the two, find out what it needs to perform its role, such as multiple network interfaces, and invest in a cheap network dumb switch and AP.