What is the best site to buy a domain name

hey all, im still pretty new to domains and have only registered one before, so i’m a bit confused about the whole setup.

i’m building a website now and need to register another domain. is it better to buy it through something like Wix, GoDaddy, Namecheap, Cloudflare, or something similar?

and once you own the domain, is there any real benefit to transferring it to cloudflare, or can you just keep it with the original registrar and point the DNS there?