Here are the steps you can take to secure your personal information on a lost or stolen device:

1. Locate your device:
   Use device tracking services to see if you can locate your missing device.
2. Change passwords:
   Change the passwords on the device, as well as any associated online accounts.
3. Report to authorities:
   File a police report to document the incident.
4. Perform a factory reset:
   This will reset the device to its original state and delete your data.
5. Backup regularly:
   Always have a backup copy of the files on your device in case it gets lost or stolen.