Hi Mohammad,
Thank you very much for splitting your questions into various topics! You’re making a great contribution to our community, and you’re also helping us to keep our forums tidy! 🙂
We thank you for reporting this issue. It seems this link has been created during the import.
To delete this link, go to Dashboard > Appearance > Menus and select the Footer menu. Then, click on this specific item and delete it. Please find the attached screenshot.
Once this item is deleted, you can add another page/link.
Best,