What does a domain name cost, and does it come with hosting?
A .com domain costs around $10 to $15 a year on its own. Many hosting plans include a free domain for the first year; after that you pay the normal rate. Domain and hosting do not have to live at the same company, but keeping them together is easier.
The domain name is your address on the internet; the hosting is the house behind it. They are separate products: you can register your domain at one company and host your site at another. For most people, everything at one provider is more practical: one invoice, one control panel, no DNS puzzles.
Watch promos for the same pattern as hosting: the first year free or nearly free, then the regular rate. Nothing wrong with that, as long as you know. Also confirm the domain is registered in your name, so you can take it with you freely if you ever move; that is standard at reputable providers, but worth verifying.
One more tip: register your domain the moment you decide on it, even if the site does not exist yet. For a few dollars a year you prevent someone else from grabbing it, and parking it at your provider costs nothing. Namecheap built its entire reputation on fair domain pricing.