Not OP, but I used Namecheap. Porkbun is also recommended I think. Setting it up is not dead-brain simple, but Proton does a very good job on explaining it step by step I believe.

IIRC Cloudflare is the only registrar that doesn’t mark up from wholesale prices, or something like that. Basically makes them cheaper than most other registrars. I think the point is that they can then sell you their other (related) services more easily — the services that actually make them money.

I use Porkbun for my domain. you can get a .xyz domain for only $2 for 1 year, though after 1 year its like $8 per year.

I’m using namesilo and it was pretty straight forward to set up. I just got it a couple days ago and no issues so far!