My website has a 522 error
This error typically occurs because Cloudflare isn't able to establish a TCP connection to your Linode (and the request eventually times out).
You'll first want to make sure that your Linode is powered on and accepting HTTP requests. You'll also want to verify that the DNS settings for your website are configured correctly in your Cloudflare account.
There are also a few excellent resources from Cloudflare that may helpful while troubleshooting this issue: