In this tutorial, we learn two methods to install a plugin on a WordPress site. The first method involves going to the Plugins section, selecting "Add New Plugin," choosing to upload a plugin, selecting the zip file from the computer, installing it, and then activating it. The second method involves manually copying the plugin files to the WordPress directory, specifically the Plugins folder. After pasting the plugin folder and extracting the files, the user refreshes the page and proceeds to activate the plugin.