Do you have a good resource for story beats/templates? Story mapping?

(I assume you mean a resource to track story beats and mapping and not a resource for generating them. Forgive me if I am mistaken as I have no advice for the latter.)

I learned story mapping/beats/pacing by trial and error and I don't recommend that because it's like banging your head against a brick wall every time you sit down to write.

The two absolute best ways to perfect your pacing and story mapping skills are:

Read a lot of books or screenplays, depending on which format you're writingOutline, outline, outline

Reading helps build the muscle for beats and mapping because you ingest it to the point that when you encounter a pacing issue, you know it. You feel it in your belly.

As for outlining, it's an age-old tool for a reason. Personally, I hate outlining and often don't do it, but those stories and scripts are often the ones that need the most editing.

Beyond that, this may sound silly because it's kind of a cliché in the business, but the Save The Cat books are full of great tools and tips for pacing, character, etc. It started as a how-to for screenwriters, but now it's a whole media empire of instructionals for writers of all genres and formats, including novels.

You could try that resource (or one of the hundreds of copycats... see what I did there?) to build up your story mapping skill to the point where you know when to ignore those Save The Cat rules.

There are also a lot of other online tools in which you can enter character info and scenes to make pacing easier. (When writing More Than Stars, which had eight—yes, eight!—lead characters, I used a program that turned the character arcs into a graph just so I could keep track of it all.)