You are asking 2 different questions
You can get broadband over the phone line, how far from the exchange matters as that affects the speed
If the area is enabled , you can get fast broadband which is still over the copper phone line into your home.
If the rate over the copper is slow ( under 10) you can ask that they give you something faster such as full fibre but that may require lots of engineering, so you would need to start the process .
Or you may already be in a full fibre area.
So phone a few service providers, get them to say what speed they think you can get now.
If you end up on full fibre they will I think just connect the fibre termination probably close where the phone comes in now
The second question is how to ensure you get good signals all round the house.
You can get WiFi boosters to help spread the signal . If it were me, I would run Ethernet cable around to key areas like where you might have a tv or computer. Then you are less limited by the WiFi .
If you get a high speed full fibre option you won't be able use all that speed if you just use WiFi , it can't go that fast , so putting some things into Ethernet cable lets you get better use , and can simplify getting good coverage