Welcome to the forum.
When you say 'web host', it usually means a place to host your own website. So instead of having your clients go to [
www.Smugmug/tracie/dklskldkld/sldlksk] etc., you could register a domain and have your clients go to something like
www.TracieCrawford.com
If that is something that you want, then you will need three things. First is to register the domain name that you want (or find one that is available). Then you purchase a hosting plan. (you can often register and get a hosting plan from the same company, but you can do it separately if you wish). Thirdly you need the actual web site. You can build it yourself, ask (pay) someone to design it for you, or you could use a template. Most hosting companies will have simple web building software and/or templates that you can use. There are also many companies that sell website templates.
My recommendation for website hosting is HostGator.com.
If you want client galleries to be part of your website, then that is something that is certainly possible. Some websites have this built right into them, or you could purchase an add-in type application (I use Photocart). Or you could use an on-line photo hosting/gallery type website (like Smugmug etc) and just link to them from your website.
Maybe you don't want to have your own website, you can still use something like Smugmug to set up client galleries etc. It just doesn't look as professional when you send your clients there.