how to add space between columns of a wordpress gallery

Hi lrileypool. One of the solutions here might help:
https://css-tricks.com/equidistant-objects-with-css/

That definitely makes sense. Thanks for the help. But, I am a novice with code…

So, if I were to use the flexbox justification method, could I just add that code into a Custom CSS area if I replaced a couple words in it?

Yes. You’ll also need to adjust the size of the images down a bit to allow for spacing. Something like this should work; adjust the max-width % as needed:

/* reduce image width to allow spacing */
.gallery-columns-5 .gallery-item {
    max-width: 19%;
}
/* equal spacing between images */
#gallery-2 {
    display: flex;
    justify-content: space-between;
}

Beautiful! Thank you so much!

You’re welcome; glad to help.