Checking if next_post is the latest post

I am trying to use WordPress to publish a webcomic. Yes, there is already a series of themes and plugins for this, but I think they are very bloated and often don’t offer the few things I want to do.

For instance, I want to somehow check to see if the next post is going to be the latest post. If it is, I want the link to just redirect to the homepage. Can it be done?

In general, I’m having trouble with navigation. I’m using two loops (one for the comic, category comic, and the other for news of the same category name).

On the main page, when clicking the previous post button, it takes you back a page. Is there anyway I can get a link to the previous POST, so it links directly to the post with the comic?

I guess I don’t really have a specific question, but more the concept. If anyone could help me understand the framework better to achieve my goals, that would be great. Thanks in advance.