How to make a Wi-Fi password to protect your internet, or change your existing password

To make a Wi-Fi password, or change your current password, you'll need to access your router's settings page using a computer.
Ars Technica

Dumb question - how do I find my ISP's I/D and my password

I have a new router and want to replace the old one. The current one is a NetGear router, and I have NetGear Genie installed. It appears I need to re-enter my ISP details - I/D and Password. Are these ...