Assuming your phone is on and online, you should be able to see its location on a map. From there, you can make it ring, lock ...

How to lock apps on Google Pixel phones or other devices running Android 15 After years of user requests, Google finally decided to add app lock as a native feature to Android 15.

For phones running Stock Android, you can use the Settings widget to add shortcuts for various settings. Long-Press on Home Screen: Long-press on any empty space on your home screen.