What do I need to do to make the scoring live?
You need to input the scores during play.
There are several ways that you could implement the live scoring...
To have true live scoring, you need to share the sheet with the players and have them input their scores as they finish each hole. This is the only way to have true live scoring. If you are using this method, it might be a good idea to create a QR code that links to the sheet. You could have players take a picture of the QR code and follow the link to gain access to the sheet. Players will need to have Google Sheets installed on their phones.
You could have semi-live scoring in a couple of ways. One would be to share the sheet with the coaches and have them enter their players' scores as they check in with them throughout the round. Another way to have semi-live scoring would be to have volunteers positioned every three holes, or at the turn that enter the players' scores as they pass by. Whomever is entering the scores will need to have access to Google Sheets either on their phones or on a laptop.