Display of image captions

Hi there,
the standard image caption display (i.e. here: https://themes.ishyoboy.com/freelo/gallery/) is in a box which overlays the image. Is there an easy way to change this (i.e. to place the caption under the image instead)?
Or is it possible to change the font size in the overlay caption? I have fairly small images and long captions, and don’t want to hide so much of the image behind the caption.
Thanks for any help!