You should stop using your iPhone right now before recovering the lost pictures to avoid them being overwritten.
You can recover your deleted photos from your iPhone 5 via the Photos app (Photo Vault). The steps are below:
- Open the Photos app.
- Tap the "Recently Deleted" album and open it with your Face ID or password.
- Tap the "Select" button on the top-right corner.
- Select the photos you want to recover and tap "Recover".
- Tap "Recover Photo" and then these deleted photos will be restored in your Photo Vault.
If you haven't found any pictures in the Recently Deleted album in Photo Vault, check if you've turned on iCloud. If had, you can also recover your deleted photos from iCloud.