NOTE: You can check this thread for a guide on how to back up data on the phone.

Restore Contacts from SD Storage:

  1. Launch “Contacts
  2. Tap “Menu” > “Settings
  3. Go to “Contacts to display” and select “All contacts
  4. Tap “Import/Export contacts
  5. Tap “Import from SD card” > “OK

Restore Media Files from SD Storage:

  1. Open “My Files” and go to “SD Card
  2. Tap “Menu” > “Edit
  3. Tick the boxes associated with the media files you want to restore
  4. Tap “Menu” > “Move” > “Internal storage
  5. Select the desired folder or tap “Create folder
  6. Tap “Move here

Restore Media Files from a Windows PC:

  1. Connect the Android phone to the PC via USB
  2. Enable “Media device” / “File Transfer” on the phone when prompted or from the Notification shade
  3. Launch the File Explorer on the computer and navigate to the media backup files on the PC
  4. Copy and paste the files to the phone storage in the folders of origin
  5. Once done, eject the phone storage and safely disconnect the device from the USB cord

See More: Samsung Galaxy A9 Pro (2019): Restore Contacts and Media Files