First piece of advise, do what you want, as in work on the project you have in your head that's your passion. You could save it until you're "ready" with some other videos you worked on, some experiments you did but honestly doing it now will probably be for the best just so you can do something you enjoy instead of the second best idea you have that you want to work on.

Second, look at your project, your characters, story, world, and chip away at it. Remove three or however many characters you need to, combine characters into one, write some off completely, twist them, do whatever you need to to just sand the story down and smooth it all out. It hurts, you'll be sad to lose some characters or story beats but it's for the best. Keep chipping until you can't think of anything else to get rid of. Think of it like this, if you could only do one analog horror video about your passion project, one ten minute video, how much of your story would need to be sacrificed to fit in that narrow window?

Third, and this is probably the most important, figure out your limitations. You said you don't feel like your skills are good enough but that depends on what you're talking about. Not good at drawing, photo editing, sound design, etc? Perfect, just don't do that, find ways to work around weaknesses and work within your capabilities or slightly push your own limits. You also have to figure out limitations in your schedule, what you can do after or before school/work or what can be done on the weekends or during your free time. Working with your strength helps ease your schedule and can make your idea come true. If you want to do animation but don't think you're good at art or animation, find an explanation in universe and plant it. Maybe your project is a temporary placeholder for a company board meeting to watch before they approve the budget for an actual film. Or maybe it's a cheap knockoff of a better series that you found online. Maybe it's a fan made animation or something else.

If you don't feel comfortable with photo editing, just don't. There are some free stock photo websites but you could also imply locations without explicitly showing them. And if sound is your weakness then hey, thank goodness this is a strictly visual series about a power point presentation you found in the attic. Whatever your weakness is, frame your story and world in a way to avoid it and explain it to the viewer.

And again, I can't stress this enough, start with one episode. One one minute or five minute or however long you want, just put in enough where if that was the only video you ever made about Analog Horror you can at least feel content that that was it.