Hi there,
you can uncheck Display Post Date for Archives and Singles in the Customizer > Layout > Blog
https://docs.generatepress.com/article/blog-content-layout/
This will remove the time stamp you see in your post meta.
You also have two meta properties in the <head>
of your site – which are not added by the theme. I assume you’re using an SEO plugin which may have options to disable that.
After that it’s down to google as to whether it ‘creates’ a date on the SERPs.