Hello @vsgreen829,

Actually, there is no separate class for the subpage so to make the title disappear in the subpage you need to target the page id and hide the title.

For example:

To remove the title from the “Yelp Review Management”, add below given CSS by going to Admin Panel > Appearance > Customize > Additional CSS.

.page-id-60 h1.entry-title {
    display: none;
}

You will find the page id in the URL by going to the single page edit screen.
Screenshot:

https://prnt.sc/lqe12a

Hope this helps.

Regards!!