How can i create my own template in powerpoint with 8 pics

I'm trying to create a template in powerpoint for my dental office, but can
not figure out how to add new boxes (the "click icon to add content" box). I
need landscape format, 3 pics on top, 3 on bottom, text box in middle with 2
pics on the sides of text. Totaling 8 pics and 1 text box. I was able to
create the layout, but just had to insert pic and resize them drastically,
drop them in their right spot, and was unable to make the template so i can
use it for numerous patients. I have to create the whole document from
scratch at this point.