Well, you have to set up the account with bluehost, install and configure the software from wordpress.ORG (bluehost has simple scripts through the cPanel that will install the software for you). Then you need to make a decision:
If you ask for a refund on your $99, you will lose your domain name and it might be as long as 60 days before the registrar releases it so that you could get it again (assuming someone doesn't grab it before you can get it). If you get the refund, then you are going to have to get another domain name. You can register one through bluehost.
You should be aware of the extra responsibilities that come along with self-hosting. You will be responsible for all installations, all upgrades, all backups and all troubleshooting. If something goes wrong, you have to figure it out and fix it. Sometimes installing a theme or a plugin will kill your site. This happens more often than people realize for a variety of reasons.
Always keep up with the wordpress upgrades. Always do routine backups of your entire site including the database. That way if something goes terribly wrong, you can restore from a backup and be back up and running in a few hours. If you don't have backups, you could well lose everything. Also, do a full backup before any wordpress upgrade and I even do one before plugin and theme installations.
WordPress has made self-hosting much easier than it was before, but there is still far more work involved and I cannot stress enough how important backups are, especially if your site gets completely wrecked by hackers or something you install kills it beyond repair.
If you have content already on your site here, you can export it from here and then import it into the new site.