It could be found in a couple places. Based on the question you’ve asked I’m guessing that you obviously didn’t create this template/theme yourself so my guidance may be tricky for you.
Also, be aware that if you remove/add the wrong character in the wrong place that it could mess-up the layout of your whole store.
I’d start by looking in “Blogs & Pages”. You’re probably looking for a page called, “Product Page Intro” or “Flower”.
If you don’t see one of those, go over to your Assets tab at the top and choose Theme Editor. Open your collection.liquid file and search through that until you find the text “Beautiful On Sale….”. Edit just that text and nothing around it and you’ll be fine.
You are right, I did not create this template/theme and I am limited as to what I can do. I will have a look in the collection.liquid file. Hope it is just a matter of editing some text. I must say I have learned a lot about coding since I began the site, but still have a lot to learn.
Thanks again, Mickmac
I know this is an old post, but others will want the answer.
Most likely you can set whether there will be a subheading by going to Customize Theme. Then from the dropdown select the Blog post . In preview click on the blog post. And one of your options (at least in OutOfTheSandbox themes -- and I assume in other themes -- you can delete the subheading words -- or put in soemting other than Subheading -- such as "The Latest News". I think the subheading wording may be global for all Blogs, so you might need to have a generic phrase -- or just delete the word "Subheading".