You need to purchase a domain--usually pd. yearly. Go Daddy, Name and Whosis are excellent choices. Mine are through GoDaddy.
Then you can choose which hosting option to use, I use their hosting options. There are different brackets--you do need to have an idea of the traffic and bandwidth you are going to need, dedicated server or community, etc. Do your research first--it will save much money in the end!! And everything adds up--FAST!! ALSO--if a forum is on the site you are building, start it how you need it to stay, changing them is almost impossible!!