How to make a random post button

Hi everyone,

I’ve googled around but haven’t seen anything super definitive on this– I have a webcomic at https://www.intheboatcomic.com and I would like to make a button (using an image that I have,) that I can add to each new post and, when a person clicks on it, it will randomly take them to any other post I’ve posted. (All my posts are tied to a single category called ‘comics’ if that helps.)

Does anyone know of a quick easy way to enact this? Is there a good plug in? I don’t know the first thing about code — even when someone says, ex: “paste this into your xyz.php file”, I’m not sure where to go to find that or where to paste the code in the file once Im there, so please be very specific in your directions.

Thanks a million!!

Mark