Welcome to this user forum.
Yes they will need to have a phone line provided first, once that is active, they will be able to order broadband.
If there is an existing route, then it may be possible to order both phone and broadband together as part of one order. That can reduce the initial connection charge.
Hi Micky, in most case the line connection/installation will be waived as part of a broadband order, ask your friend to place the order and any setup costs will be listed before the order is placed, all the current broadband deals have free activation except for essential fibre and standard broadband which is £29.99, the others just include the £9.99 postage fee.
You can also have any one off costs added to the first bill, so you don't have to wait to place the order 🙂
Keith clearly types faster, duplicate answer.