I'd really recommend doing some reading. Understanding Comics by Scott McCloud is the go to starting book, and a pretty easy read. Even as a writer, understanding the basics of paneling will do you a lot of good.
Everyone scripts differently and it really depends on what you want. Some people write 'three page fight scene, x gets stabbed' while others write paragraphs on what every billboard will say. It depends on what's important to your plot, and on your artist's preferences. You should learn to write by the panel and to feel out how your pacing will work for comics.
If you aren't planning on paying an artist, getting artists excited about your work is a good first step. I am somebody who would almost never collab without pay, but I'd may an exception for a few writers whose work I'd be even more excited to work on than my own.
If you are planning on paying, you'll want to figure out a reasonable pay rate. The low end of pay is 40$ a page. Artists might ask for less, but 40$ a page ends up pretty low an hour. Assuming an average page is about 6 panels, that's about 6.5$ bucks a panel. Webtoons are about 30-40 bucks a panel, so if you want to give an artist decent pay, I'd expect to pay at least 200 bucks an episode. (which, if they draw at my speed, would still only be paying them like 2$ an hour)
Woof. And that's why I draw my own.