This video shows how to import a database on Namecheap Shared Hosting
You may also need to check:
How to create and maintain MySQL Databases in cPanel https://www.namecheap.com/support/knowledgebase/article.aspx/9363/2180/how-to-create-and-maintain-mysql-databases-in-cpanel/
How to import and export a database via SSH https://www.namecheap.com/support/knowledgebase/article.aspx/9184/2180/how-to-import-and-export-a-database-via-ssh/
How to manage databases with phpMyAdmin https://www.namecheap.com/support/knowledgebase/article.aspx/9540/2180/how-to-manage-databases-with-phpmyadmin/
