We generally recommend against having multiple H1 headings on a page. The reason for this is that multiple H1 tags can dilute SEO value and potentially confuse search engines about the main topic of the page.
To find whether you have multiple H1 headings on a page, you can follow these steps:
Open up the page in question
Right click
Click on ‘inspect’
If you’re using a Mac, do Command+F and if you’re using Windows, do Ctrl+F
Type <h1> into the search bar and click enter
When you click enter, if you only have one H1 heading, you should see ‘1 of 1’.
If you do have multiple H1 headings, you’ll be able to use the arrows to show you through the different H1s that you have.