Every GUDHOST site has built-in page caching and a content delivery network (CDN), so pages load quickly wherever your visitors are. There is nothing to install or configure.
If a change you made doesn't show up straight away, wait a few minutes and refresh, or open the page in a private browser window. If the old version still shows after that, open your site under Websites in your account and press Clear cache under Performance.
Please don't install a separate caching plugin: it conflicts with the built-in cache.