Follow these steps to assign a user and privileges to a database in cPanel:

1. Log in to your cPanel account.
For instructions on how to log in to your cPanel account, please click here.

2. Under the Databases section, click MySQL Databases.

3. Scroll down to the end of the page. Under Add User To Database, select a user from the dropdown list and select the database where you wish to add the user.

4. Click the Add button.

5. Under Manage User Privileges, mark the checkbox for ALL PRIVILEGES, then click the Make Changes button.

6. Your user will be added to the database with its privileges. You can verify this by returning to the MySQL Database page under Current Databases.