Set up super page cache for cloudfare

Need an experienced person to help set up the WP plugin Super Page Cache for Cloudflare. I have the Cloudflare account set up, access to current DNS and CNAMES records. Just having troubles getting it all to work. I'm guessing that not all of the DNS records were recorded into cloudflare. Bottom line: When I change the nameservers, the site no longer loads. Even after 24 hours. Would like to initiate the transfer in the middle of the night Dec 31 and Jan 1 U.S. to minimize site downtime. (Have all the settings ready to go, so I can change the nameservers at that time)