Go to "Settings" on your iPhone. Tap on your Apple ID at the top. Select "iCloud" and then "iCloud Backup." Turn on "iCloud Backup" if it's not already enabled. Tap "Back Up Now" to initiate an immediate backup to your iCloud storage.
Connect your iPhone to your computer and open iTunes (or Finder on macOS Catalina and later). Click on the iPhone icon in the top left corner. Under the "Backups" section, choose "This Computer." Click "Back Up Now" to create a full backup of your iPhone on your computer
Keep your iPhone connected to Wi-Fi and connected to power. Ensure "iCloud Backup" is turned on (check under "Settings" > "Apple ID" > "iCloud" > "iCloud Backup"). iCloud will automatically back up your device when it's charging, locked, and connected to Wi-Fi.
Consider using third-party cloud backup services like Google Drive, Dropbox, or OneDrive to store your iPhone data securely
For important files like photos, videos, and documents, use services like iCloud Photos, Google Photos, or file storage apps to back them up separately from your regular iPhone backup.