You can create default settings to use each time you create a new gallery on a per section basis. To get to the default settings, click edit under the section name in the left menu of the Site Content section.
Default Page Text When Creating New Pages
Here you can set text that will be added to the text of a gallery when created.
Default Expire & Private Page Settings
Here you can set the default for how many days to set the expiration date, password protected settings, enabling passcode photos.
Set the option to have watermarking automatically enabled when uploading photos.
Default Price List
If you have multiple price lists, you can select the default one to use when creating galleries in the section.
Default Page Status
Here you can set the default page status to Published when creating new pages / galleries.
Default Shipping Group
If you have creating different shipping groups in Settings -> Shipping, you can select the default one to use when creating new galleries in this section.
There is a tab across the top for Photo Defaults. These are the default photo display settings when creating a new page / gallery. Here you can also enable / disable social sharing of photos, search and more.