Forgetting your lock screen PIN can be stressful, but don't panic. First, try to remember any possible combinations. If that fails, check if you have enabled the "Forgot PIN" option, which may prompt you to use your Google account or a backup PIN to unlock your device.
Another option is to use Android Device Manager or Find My Device (for Android) or iCloud (for iOS) to remotely lock or erase your device. As a last resort, consider factory resetting your device, which will erase all data but allow you to regain access. Always keep a backup of important data to prevent loss.