Blocks?

I am guessing I am in the wrong forum, but I have been chasing my tail for a couple of hours and can’t figure out where to go.

Mailchimp provides me with a nice sign-up form, and a nice shortcode with it.

I would like to create a block, with an assigned shortcode that I can quickly slap into my pages, which is *not* a form/sign-up, but which instead promotes a book I have written. It would seem that the software for this would be in the basic WP software, but I’m over my head.

Thanks for any help.