Before creating your first gallery you may want to look over the Settings page options and choose anything that has to do with file renaming because that happens when you upload your images for the first time. You will find that option under the Attachment File & Title Renaming area of the Settings page. It is not required simply a suggestion.
Make sure and choose any options you would like and SAVE the page before moving on to create your first gallery. Now we will create our first image gallery in Step 2.