First login to DirectAdmin, then click on Softaculous, then click on the Install button under WordPress.
You will be prompted to enter some information. First you will need to choose the Choose Installation URL to use (we recommend selecting a domain beginning with https://). If want to install WordPress to the root of your web site, change the In Directory to field blank, otherwise specify a folder name for this field.
Next scroll down to the Site Settings area and enter the Site Name and Site Description for your new site. Under Admin Account choose a username and password for your WordPress admin area.
Under Plugins select any plugins you'd like installed off the bat. We highly recommend Limit Login Attempts plugin. More plugins can be added later through your WordPress admin area.
Finally, click the Install button.
After WordPress installs you will be provided with to links, one to the WordPress site that users will see, and one to the admin side used to administrate the site. Please make note of these links for future reference.
You can refer to the WordPress Quick Start Guide for information on creating content, styling your site, and adding additional features using plugins.