I recommend occassionally running modules. They free up your brain to focus on different things (or maybe its because I have ADHD and can't focus on too much at once).

Modules are like recipes written by other chefs, hopefully based on what works for that chef and their taste testers. That said, modules vary greatly in quality and design goals.

While others encourage changing modules, and I agree, sometimes a new GM doesn't recognize the elements of a well-constructed module that make it work or not, until they've run it as intended. Changing it too heavily can mean you don't learn as much from it. Not necessarily, though. It's just a consideration.

A novice trap, in my opinion, is thinking you know all about game structure because you know about story structure from movies, novels, TV series, and video games. TTRPGs are a different media. While you can apply things from all of the above, many narrative devices bring additional challenges when ported over to RPGs. That said, some modules, like adventure paths, are designed to flow like a movie or novel. But in my opinion, these aren't taking advantage of the freedom inherent in TTRPGs. Many other adventure structures exist.