ERR_NAME_NOT_RESOLVED after DNS change to Cloudflare

hi all, new to all of this so thanks in advance for patience with my lack of knowledge.

I changed my Name Servers to those of cloudflare and as of now they have not been confirmed but are still trying.
Is this why my website does not load and I get the ERR_NAME_NOT_RESOLVED message?

https://community.cloudflare.com/search?q=ERR_NAME_NOT_RESOLVED