Every business owner picking a domain name goes through the same five minutes of panic. The .com is taken. The clever pun is taken. Somebody in Ohio has been sitting on yourbusinessname.com since 2004 and won't sell it for less than four figures. Deep breath. Most of this matters less than people think.
Here's what does.
Match your business name, or get close. If you're "Rosa's Bakery," people are going to type rosasbakery.com before they type anything cleverer. A domain that matches what's on your sign is a domain nobody has to guess at. That beats a punny name every time, even a genuinely good pun.
Skip the hyphens and the tacked-on numbers. rosas-bakery.com and rosasbakery4u.com both work as URLs and both cost you customers, because plenty of people will type it wrong from memory. If someone hears your domain out loud, off a radio ad or a friend or the side of your truck, it needs to be spellable without a spelling test.
.com still wins, but it's not mandatory. If your exact .com is gone, a clean .co or a locally relevant extension like .studio or .shop is a fine second choice, as long as the name itself stays simple. What's not a fine second choice: a weird misspelling just to land on the .com you wanted.
Now the part people skip past. You don't buy your domain from Cantrip, or from Wix, or from whoever builds your site, and that's on purpose. You buy it from a registrar (Namecheap and GoDaddy are the two most people land on) and then point it at whatever you're building your site with. That separation matters more than it sounds like it should: if you ever switch website builders, your domain isn't hostage to the one you're leaving. You repoint it and move on. No ransom, no rebuilding your brand from a new URL.
Pointing it is the part people dread, and it's simpler than it used to be. You add the domain in your site's settings, update a DNS record at your registrar (an A record, pointed at an address your builder gives you), and wait for it to take effect: usually minutes, sometimes a few hours. SSL, the thing that makes the little padlock show up and keeps browsers from yelling at your visitors, gets issued and renewed on its own once the domain's connected. You don't buy a certificate. You don't renew it every year. You don't think about it again.
One honest caveat: DNS looks scarier than it is right up until it's wrong, and then it's genuinely annoying to debug at 11pm. If your registrar's dashboard shows you a wall of record types you don't recognize, that's normal. Copy the values exactly as given and don't improvise.
The whole job of a domain name is letting people find you and trust they landed in the right place. It doesn't need to be clever. It needs to be spelled right the first time, sit behind a valid certificate, and belong to you, not to whatever tool you happened to build your site with this year.