Domain and Web Server are diferent provider

Hello Mates.

I bought my domain at World4You.com.

I get my server service from Linevast.de.

The name servers of Linevast are stored at World4You.com.

If I delete them and change them against those of Cloudflare, will there be problems with my server?

Thanks for your ideas!

Take a back-up of existing DNS records (A,AAA,TXT,CNAME,MX)

Then update CF NS.