How to get a Domain Name and cost

This would be my first time of actually having MY OWN business, and not runing someone elses, and I have a lot more to learn than I thought. I dont know where to turn for the answers, so I hope this will be a start. My question for now is, where do you go to actually get your domain name, how do you pick who will host it, and how much do these 2 seperate services approx. cost. Also, is the company that hosts the website, will they also keep track of how many visits your site gets, how many times it gets bookmarked, etc. all of the fact and figures that lets you know the effectnivness or lack of, or the site, and advertising, pricing, etc.. In my case it would be a retail site. Im sorry so many questions, but if someone could muddle through all I spewed out on the page, I would appreciate it. Thanks.