So maybe you'd like your own, easily-identifiable, home on the web. Great!
Domain addresses come in different formats: .com, .net, .org, .co.uk and so on. Dot.Com is probably the most popular - it's easy to remember, and it has a global feel to it. Dot.Com is often used by commercial businesses - retailers especially. Dot.Org tends to be used by Service companies or Educational sites. But there's really no hard or fast rule, and your choice will often be dictated by cost, which can range from "free for the first year then £10 per year thereafter for three years", or "£12 per year for two years' and so on. You can buy a domain from a broker (like GoDaddy.com) and attach it to a website you've built with, say, Wix. That can be a bit fiddly, so I tend to go for the simple option, and buy the domain name from whichever web builder I'm going to use (Wix, SImplesite, WordPress, etc.) - there's not a lot of difference in price.
So, if you go for a domain website, I will charge you whatever the domain and hosting fees are (and you can choose whether to go for one, two or three years). Some also offer a monthly fee, but you don't tend to get the first year free with those. I'll be totally up front about those costs, and you'll be able to see them on the web builder site. I'll also charge you for my time in setting the site up (up to an agreed maximum) and if you need periodic editing or updates, we'll agree a charge for that, too. You are of course free to compare my charges to other similar businesses.