What size should event photos be for Squarespace?

Between 1500 and 2500 pixels wide

Images smaller than 1500 pixels may appear blurry or pixelated when they stretch to fill containers, such as banners. In most cases, Squarespace will reformat large images to a maximum width of 2500 pixels. May 7, 2023.

Adding drop-down menus to your navigation with folders

To add a folder:

• Open the Pages panel and click the + icon.

• Click Folder.

• The empty folder will appear in the pages panel. Enter a name for the folder to display in the navigation.

• Add pages to the folder

Folders aren't pages and it's not possible to add content directly to them. Instead, when you add pages to a folder, they appear as drop-down menu items.

To add an existing page to the folder, drag and drop it into the space below the folder. To add a new page to the folder, click Add Page below the folder. To change the order of the pages, drag and drop them within the folder.

It's not possible to nest folders within folders.

https://support.squarespace.com/hc/en-us/articles/205813818-Adding-drop-down-menus-to-your-navigation-with-folder