Hey Amin,
Please go to Appearance > Customize > WooCommerce and ensure you’ve set the Product Images settings. If you have not done so yet, please also update WooCommerce.
Warnings does not affect the functionality also and it’s recommended to turn them off in live sites. You can disable the error display while keeping a record of the them in an error log. You can see how in https://codex.wordpress.org/Debugging_in_WordPress. Specifically see the Example wp-config.php for Debugging.
If that does not help, please try testing for a plugin conflict. You can do this by deactivating all third party plugins, and seeing if the problem remains. If it’s fixed, you’ll know a plugin caused the problem, and you can narrow down which one by reactivating them one at a time.
As a last resort, please give us WordPress Admin and FTP access in a Secure Note.
Thanks.