Yeah, I went through 4 years of film school, and I only have a guess what a beat sheet is. Sounds kind of like an outline.
But yeah, everyone's process is different. And sometimes it's a good amount of work figuring out what's best for you. The last two scripts I finished, I wrote one from beginning to end without any outline. And I wrote one from treatment, to outline, to scene outline and filled in the scenes last. And I'm still not sure which is best, both had super drawbacks.
So if you think a beat sheet or whatever will help, give it a try. It's a trial and error process!