How to import Informations data (date and time) of a photo into PAGES?

As it turns out when you drag and drop a photo from the Finder, or from the Media toolbar into a Pages document, the original filename and location (path) to the file are lost, and a generated UUID string replaces the filename while retaining the extension.

When you use the Insert menu > Choose… and obtain a photo in that manner, all you have is the filename and extension with no path information.

Both paragraphs give you no means to obtain further information about that Pages document image internal to the Pages document with regard to its internal or external creation date. It is possible to write an AppleScript that lets you independently select the particular image file and return its internal EXIF creation date as a formatted string.

If that code were in a Quick Action, you could right-click in the Caption panel, select the Quick Action from the Services sub-menu; be prompted for the image, and have the formatted creation date written directly into the Caption panel.

Mojave's Quick Actions are just really HIgh Sierra's Automator's Services with some additional features from Finder. But service is a service…

I see no means to automate the tedium that is facing you with a thousand images. Once the image is in the Pages document, I cannot get any information about it. One approach is to click into a folder containing your images with Preview's open panel and set the sort order to the creation date. Then open these images in Preview, and set the View to Contact Sheet. Left to right, and top to bottom, your displayed images will be in Finder-based creation date order. When you press ⌘+i in Preview, it opens an information panel where you can see the actual date/time of the creation date, and if you need the DateTimeOriginal EXIF information internal to the image, that is also available from that same information window.

Putting a thousand images into Pages will probably cause it to crash, or be so horribly slow as to be unusable.

Is this the date-time original date that the photo was taken, from the internal EXIF image data, or the current filesystem creation date?

What is the date string format that you want to see in the Caption?