It's so cool to read everyone's experiences <3
I've seen some people in the same situation as me up there. I started working on my story around 2013. I only had a couple characters designs, a very vague idea of what I wanted the story to be like (with some super detailed parts tho) and... That's pretty much it x'D I was 13 at that time so I just had fun and experimented a lot, I wanted to do a story as cool as those on the animes I watched lmao.
I kept on working on the story very slowly the next years. I was kinda stuck with what to do in some key parts, didn't have any of the villains designed, for example (I knew they had to exist and what they'd do but I didn't know nor their personalities nor their looks x'D). I did some big progress in a couple ocassions, because inspiration bursts happen, but that's about it. I even tried to start the comic a couple times but it came to a stop very very shortly after starting because... Well, it wasn't ready at all.
In the last couple years I do have been working on my story nonstop tho (mainly thanks to my gf and roleplay lmao. It's is the best way to develop characters and story for me, it makes my brain work and it's super fun to do). Thanks to that I was able to get to know my villains (finally), flesh out a script of the whole story from start to end, and get started I've been drawing the comic sinceee... Half a year ago, more or less, and I'm having a blast <3
Wish you all the best with your stories <3 you can do this