For starters, it seems like your website is using Cloudflare right now. That means Cloudflare is responsible for installing an SSL certificate that secures the connection between your browser and Cloudflare. If that’s not working for any reason, please check it with Cloudflare.
That said, please also note that any DNS changes can take up to 72 hours to take effect. So if you only recently switched to Cloudflare, your browser may still be connecting to our servers, not Cloudflare, so you’ll need to wait for that to fix itself.
Finally, please note that Cloudflare and WordPress don’t work well out of the box, because WordPress doesn’t like Cloudflare’s Flexible SSL and Cloudflare’s Automatic HTTPS Rewrites feature doesn’t work well most of the time. You can setup Full SSL to fix this: