When you buy a domain, you'll buy it from a registrar. These are the folks who make sure that one person (and only one person) owns a domain. They are all pretty much the same. There are some differences in their customer service, and the UX of navigating their site--but they're pretty much the same.
Often (or, by default), you'll use your registrar to manage your DNS. But you don't have to. (I'll have to cover that later)
Here's a list of common registrars:
- GoDaddy - These guys are probably the most popular, but that doesn't mean they are the best.
- Google Domains - Exactly what you'd expect from Google: easy to use. If you're already heavily invested in the Google ecosphere, this might be a good choice.
- Ionos (formerly 1&1)
There are other blogging platforms (Blogger, GitHub, etc), but WordPress is the most popular. In fact, WordPress is the most popular content management system (CMS) in the world, and it powers 30% of the internet.
If you are a data blogger, chances are, you aren't a web developer or even a front-end developer. You're going to have questions, and there is a whole community of bloggers who are eager to help you. They aren't web developers either, so their experience is mostly limited to the platform they use for their own blog--and most of them are on WordPress.