Info needed for new home installation

Hi everybody! My husband and I are closing on our new house next month and I’m looking for some information on getting WiFi installed! My parents built a new house in the same addition as we are and had their WiFi installed earlier this year. When they had theirs installed the AT&T man drilled a hole through their outside wall and installed a box on the outside of their house. By doing this, they can only have their modem hooked up in that one room and the ports in all the other rooms cannot be used. My mom asked if they could run the cables through the walls and to the attic so they could use all their ports but the man said At&t employees are no longer allowed to do this and she would need to have a network engineer come out.

As we are getting close to closing on our house, I want to be prepared to do what we need to do to have ours installed through the attic! We would like to be able to use every port in each room if we want and the room we plan to have to modem in does not have a port on an outside wall .

Can anyone offer any advise on this situation? How do we get our house set up properly? Who should we call? Thank you for your help!