I can definitely look into this with you. Do you have an example of how you would like this to look or what you would like it to say?
I believe the best way to do this would be to add a Rich text section to your theme and move it to the top of the page. With a rich text section you can add in a new heading or a body of text. However, there are other sections you can use as well if they work better for you.
To do this you’ll want to open your theme editor by going to Online store > Themes and clicking Customize next to the theme you want to edit. You’ll want to make sure you are editing your DefaultCollection page template and then you will see the Add section option on the left. Once the section is created you can move it to the top of the page by clicking the icon with the six little dots and dragging the section to the place you would like it to appear. If you don’t want to keep the body of text, it can be removed by just leaving that “Text” area in the rich text section empty. You can read more about using sections and blocks on this page.
If you would like the header to be the collection’s name, this can also be done by clicking the Collection section on the left and un-checking the Hide title box on the right.