Gallery ID’s

Hello,
This might sound a dumb question but… where are stored galleries? where can I see gallery ID’s ? How can I display two or more galleries in one page?

I’ve been using this for months, but only using the image gallery upload function on the bottom of each page, and then use shortcode “[easy_image_gallery]” on the place I wish to show those photos, on that same page.

Am I missing something?
Thanks!