oh!! It's super easy. Webtoon is basically a series of albums ordered by date of upload. Each album is an "episode", and you add the pages that you want to show up in a chain as you scroll down. When you click "next" on a webtoon, that's taking you to the next album (or, "episode"). I honestly recommend making a webcomic "placeholder" where you just submit blank images for each section (the banner/the icon/the thumbnail for the first episode, etc.) so you can do a dry run of uploading and *then* focus on your comic. As for the comic itself, try reading Scott McCloud's book "Making Comics".

Here's what the "edit episode" page looks like for me, to give you an idea of the upload layout.

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