Hi aubren160,
Thank you for using the Apple Support Communities! I understand you lost your AirPods case, and I'd like to help.
Find My may not able to locate a lost Charging Case, as it's more targeted towards finding the lost AirPods themselves: If your AirPods are lost - Apple Support. You can purchase a replacement Charging Case if you are unable to locate it. More information about this can be reviewed here: AirPods Repair - Official Apple Support. If you decide to stop in to your local Apple Store Store List - Apple Store - Apple, or Apple Authorized Service Provider Apple - Find Locations - Location Selector, you’ll need your serial number, so be sure to bring your proof of purchase, or original AirPods box, along with your original AirPods. Or, reach out to discuss options here: Contact - Official Apple Support.
Best regards.