Add large title below large group of small photos in Lightroom Classic?

A couple of ideas come to my mind-

*In the Print module- Create a 'Custom Package' by adding any number of cells that you want (Resize and relocate as wanted)

*Design an ID Plate with text or a graphic to add anywhere on the print page.

Or use the Print module to export a jpg from a 'Contact Sheet' of images, import the JPG to the catalog, Use the combined image to Export as JPG with Watermark or ID Plate. Or make use of the Mogrify Plugin to add text to an exported image. MOGRIFY 

* Use the Book Module for a JPG Export with a Custom Layout of added cells and

* Add [Page Text] at the base of the page. Set Font and text size (Large) in the Type panel.

Experimenting is learning!

Please explain in much more detail what you want to do.

If you post screenshots, do not attach them – use the Insert Photos button in the toolbar to embed them in your post.