Should I learn JavaScript?

It's a great tools to have on hand, even if you use it only on rare occasions. Just a small amount of very simple script can save you tons of time and complexity when developing certain types of interactions in Storyline.

One thing to consider: If primarily you're interested in data manipulation, then it's as Jonathan suggested; some basic JavaScript knowledge and help from a LLM will cover many of your needs. However, if you're interested in more visual/graphical manipulations, then you might need to learn a bit about some related areas as well to get the job done. These may include HTML, CSS, and Storyline itself.

This ELH site has some good resources, including those related to JavaScript, in its learning resources. Look at Storyline Skill Builders | Articulate - Community , particularly under Guest Webinars for some info about using JavaScript in Storyline.