2.) Click on Plugins on the left hand side, then click Add New.

3.) In the search field, search for "W3 Total Cache":

4.) Click Install Now under the W3 Total Cache plugin name:

5.) Activate the plugin:

6.) On the left hand side, click on Performance and select General Settings.

7.) Scroll down to Page Cache, ensure it's enabled and then click Save All Settings.

8.) Scroll down to Browser Cache, ensure it's enabled and click Save All Settings.

9.) Test your website to ensure all functionality is still available and working as expected.
Please note: If you would like any website changes you have made from now on to take effect immediately, you will have to clear the cache for that particular page click clicking on Performance at the top of your screen (whilst logged into Wordpress) and click Purge From Cache.