Just go for it. Sometimes we get so precious with our ideas--but you'll get older and will want to be doing different things. Make what you want to make right now, while it's still the season for the story in your head.
And I would just write with where you are right now. With the skills you have right now. Maybe it's not pro--but just edit down the story, so it still works with where you are right now. So maybe instead of doing like a huge long epic--do just a short story from that universe of like 3-4 pages to start, so you get the hang of pages. Instead of complicated character designs, go simplified, for now, and lean into graphic design. You'll get the techniques of the big comic creators eventually, but for right now, make something at your level. And if you're level 1, do a level 1 comic where you're just learning how to set type, set up a page, make it coherent--that stuff takes time to learn, and it takes small and simple projects to learn.
And when it comes to drawing--practice your characters in standalone illustrations. Where you don't have a deadline, where you can play around with different mediums and different styles--it's a big ask to do a whole comic with consistent character design if you don't have experience, so doing one shots of like...1 or maybe 2 panels that are more illustrations than they are comics are a nice way to break into drawing characters.
Eventually, as you get comfortable, you can stretch yourself to draw longer comics, more detailed comics, and in a much quicker amount of time. But to start--you don't need to build Rome in a day.