Is Home an app and can it be deleted

Home is an app.

Home app - Apple

And you can delete it:

Delete built-in Apple apps from your iPhone, iPad, or Apple Watch - Apple Support

Ratsneve wrote:

How do I delete this from forum?

You don't. Only the Hosts, the Apple employees who run the forum, can do that. They generally only do so if a post violates the Terms of Use.

How do I bookmark discussions.apple.com?

That depends on what browser you're using. The command in Safari is command-D.