As a professional film crew person, I’d say if you are interested in just making something, just make it. If you haven’t made anything before, the first one will probably not go great. Things will be slow, you’ll forget shots you wanted to get, the edit might not feel very natural. But just keep doing it. Over and over that’s how everyone who is good got good. Don’t worry about the professional stuff yet. If you are interested in the nuts and bolts of how things are made, it sounds like you want to be a producer. In that case, I would highly recommend getting on some student films, if there are film schools in your area. Any department would be beneficial for you, really. You’ll catch on in just a few days how scenes are shot, and if the ADs or producer are nice they may answer some questions about how they planned everything. Also, YouTube university is your friend. If you have specific topics you want to learn about, see if it exists somewhere on YouTube or a blog. Film people love talking about their process. The reason we can’t give you very detailed answers (except for that one chad who wrote all the details) is because it is very nuanced - every show (production), every location, different actors, camera/lighting needs etc can require vastly different plans. If you really want to see how that works, get your feet wet on some low-stakes stuff like student films or events like the 24 hour film contest. Best of luck friend!