Google Maps API get current location

Hi guys!

I'm really new to this. I was taking the PHP MySQL course and then I did this Google Maps tutorial: https://developers.google.com/maps/articles/phpsqlsearch_v3

I did the tutorial successfully! I have phpMyAdmin and localhost:8888 running and it finds the address I input and shows the markers where they should be :)

https://github.com/summerspirit/super-octo-lamp

What I need it to do though is get the user's current location, show the markers near that and only use the input address button as a backup if there's an error.

if (navigator.geolocation) {
  console.log('Geolocation is supported!');
}
else {
  console.log('Geolocation is not supported for this Browser/OS version yet.');
}

https://developers.google.com/web/fundamentals/native-hardware/user-location/obtain-location?hl=en

What I can't figure out is where to put the geolocation. Do I need to attach it to my html button? Does it need to be part of the load function?

My understanding is I need the current user location to be the center point for the map?

Any help/tips/direction would be much appreciated :)

Thanks!