1. Download and unzip the Opencart Lastest package if you haven’t had it yet.
  2. Create a database on the MySQL server for OpenCart to contain data of store. We will use this information of database later when we are configuring OpenCart by using the auto-installer.
  3. Find and rename the file config-dist.php to config.php and admin/config-dist.php to config.php
  4. Upload these Opencart files to the desired location on your web server:
    • If you want to integrate Opencart into the root of your domain (e.g. http://example.com/), you’ll move or upload all contents of the unzipped Opencart directory into the root directory of your web server.
    • If you want to have your Opencart installation in its own sub-directory on your website (e.g. http://example.com/subdomain/), you’ll create the sub-domain directory on your server and upload the contents of the unzipped Opencart package to the directory via FTP.
    • Note: If your FTP client has an option to convert file names to lowercase, make sure it’s disabled.
  5. Run the Opencart installation script by accessing the URL in a web browser. This should be the URL where you uploaded the WordPress files.
    • If you installed Opencart in the root directory, you should visit: http://example.com/
    • If you installed Opencart in its own subdirectory called subdomain, for example, you should visit: http://example.com/subdomain/

That’s it! Opencart should now be installed.

Read more from this link:

OpenCart Documentation Installation/