Cloudflare Page Rules and Caching (Free version)

First, you should optimise the performance of your website and the server configuration. We recommend you read and follow suggestions at: https://www.vpsblocks.com.au/support/Knowledgebase/Article/View/311/0/improving-website-performance

Once that is done, you can greatly increase the speed your site is served, and reduce the load on your server by utilising the CloudFlare CDN and incorporating specific page rules for Wordpress you can dramatically speed up delivery and protect your site from hackers.

We recommend you read the article by Erick Valois on exactly how to do this: https://ttfb.io/blog/how-to-set-up-cloudflare-to-cache-wordpress-pages/