I’ll assume that you’ve created your webcomics from Settings>Webcomic.
To accomplish having the latest comic on its own main page, I created a blank page with a title.
Below the main edit box, there’s an “Inkblot Options” if you are using the inkblot theme. You can choose “Show the most recently published comic” from that dropdown.
Then you can just link to that page.
Hopefully this helps.