Adding text above gallery post in home page

I am trying to add a blurb above a gallery post on my wordpress website but I do not know what I have to do to modify the code, I believe I am to modify the content-gallery.php

Essentially, I want it to look like:

TITLE

Blurb

First picture of the gallery

Please help.

Also if anyone wants to see the website I am referring to, this is the link:
https://www.spreadthemusic.ca/