good question actually, and welcome to the site
you don't have to do anything to "make" your gallery, as a member you just have one. it consists of any/all cards you've uploaded. to see it, just click the My Gallery link on the gallery page (this is new functionality, I tweaked the gallery settings after first reading your post).
you *can* create your own personal albums as well. think of an album just as you would a physical photo album, and all your albums together make up your gallery.
to create your own album, click the Start An Album link on the home page or click the Album Admin link in the gallery (or go there
right now). You'll see a link to Add Album. From there you can put in a name and description and also choose whether you'd like the album to be personal or private.
that's it! if you have trouble or any other questions let me know.