To use WordPress, first you need to find a hosting provider.
Then WordPress needs to be installed on your web server.
There are 2 ways of doing this:
1. You can do it "manually" - as explained here: Installing WordPress
2. Alternatively, if your host provides an application called Fantastico, then this is the way to go.
With my hosting provider, you just log into your hosting account, then go to Fantastico & select WordPress. All you have to do is choose a username & password, and a folder name (the folder is then created for you). Dead easy.
If you need a good host, then I suggest you try Site5. I've been with them for just over 10 years & found them to be very reliable, with great support. A couple of things to note - they're based in the States & support is online only. However, location is irrelevant in my opinion - as long as it's politically stable. The online support is very good, & they always reply very quickly.
Their fees are very reasonable - you can get hosting cheaper in the States. More bang for your buck.
I've used them for hosting "normal" websites, but I've only just started using WordPress. Using Fantastico with them got me up & running within a few minutes.
Hope this helps.