How to connect server and router? If server ip was 172.16.11.1 and router ip was 192.168.1.1?
How to block some website on client computer?

Blocking sites can be done many ways. Do you want to block sites containing content like porn or hate speech? Or individual sites ?

There are free firewalls that can do this for you. Or you can set up a proxy. Also a good suggestion is to use a whitlist. Whitelists define all the sites that are good, and then blocking all the rest.