Hi there! Welcome to Netdata and our community!
The web server doc has information about customizing the standard dashboard. That section has information on overwriting the default names and text by editing dashboard_info.js.
Regarding the favicon, I’m not 100% sure this works—I’m not sure anyone has requested this before—but you should be able to navigate to the web server directory and replace the favicon.ico that already exists. By default, that web server folder is /usr/share/netdata/web.
Let me know if that helps! I do have a pending PR that helps to better organize some customization options, so maybe your use case ends up contributing some content to that PR.