These are the steps which need to be run though to perform the SEO Dev Checklist.
You can test your progress here: https://developers.google.com/speed/pagespeed/insights/
And here is the original SEO checklist for reference: https://docs.google.com/spreadsheets/d/1er2moYivqD_eDF3chigB0RNlH0lwJ5Z_HrSsyAMqtiA/edit#gid=0
If the site is using cloudflare then you want to use their SSL, you will need to create an Origin certificate and key in the Cloudflare dashboard following the steps below:
Use these for your titles and descriptions in your meta tags
<!--|if $meta_title != ''|--><!--|$meta_title|--><!--|else|-->Company Name: <!--|$structure|--><!--|/if|-->
<!--|if $meta_description != ''|--><!--|$meta_description|--><!--|else|-->Default description<!--|/if|-->
Place this code in the head in of your page templates (if it has pages with no content).
<!--|if $structure_directory == "page-with-no-content"|-->
<meta name="robots" content="noindex">
<!--|else|-->
<link rel="canonical" href="<!--|$canonical|-->"/>
<!--|/if|-->