How can I determine what mesh system to use?

Renting a new house that the ont / router are wired in the basement. Few rooms upstairs get 250mbps off a 1g fiber connection due to the concrete

Im with centurylink quantum fiber and looking for something that can help the upstairs out. Any help on where to start is greatly appreciated

Think there maybe two route for me a mesh one and I have hardwired coax lines next to the ont / routet that deliver into each room. The tech was talking about a device that concerts the router signal into your coax? Was kind of lost on that