The steps for installing a new WordPress plugin are always the same…
Go To Plugins Section
In your WordPress Dashboard Go to Plugins -> Add New
Search for the Plugin
Type in the plugin name in the search box on the top right of the screen.
Look for for the plugin you searched for in the search results.
Install and Activate the Plugin
When you find the plugin you want, use the Install button to install it.
Once the plugin has been installed successfully the button will then change to Activate. You also need to activate the plugin in order to use it.
Finally you will see that the plugin is now Active and ready to use.
Depending on the plugin itself it may have configuration options under the main Settings section. A large plugin will have its own section in the WordPress dashboard. Others can be found under Tools. Check the plugin documentation to see where to go to use the plugin.