SSL On Original Host Vs Cloudflare (Settings?) Problems

I recently (a few months ago) pointed DNS to Cloudflare and it has been a great help. However, over the past week, I’m getting warnings regarding the expired (now expired I think) SSL certificates I set up with my host originally. Visitors to the site are being warned of the lack of security. I thought I’d set up Cloudflare’s equivalent. The settings page says, “ Your SSL/TLS encryption mode is Full”. I’m afraid I’m out of my pay grade now and would like some recommendations if anyone has them to offer.

I can provide screenshots, however, there doesn’t seem to be that option.

I hope you mean this:
https://developers.cloudflare.com/ssl/origin-configuration/origin-ca