Yeah, if you want your own domain, you have to pay at the very minimum something like $1.50 per year. But if you're fine with *.somewhere.com, that can be done for free.
You pretty much have to use a hosting website, but there are ways around it, depending on what you want to do; if you're thinking of something that would constitute a good bit of traffic (150+ unique visitors a month), you might really need to buy hosting (a frequently recommended one being Dreamhost). If not, you could go with a free host (there's a lot of them; I personally use 000webhost). If all you want is a blog, Blogger would do.
And lastly, the wildcard is something like Dropbox. I haven't looked into it too much, but here's an article from Lifehacker: http://lifehacker.com/5860139/host-web-pages-for-free-within-dropbox-with-droppages-or-pancakeio