Well, I don't know much about Lezhin but a quick visit to the site tells me that it's pretty much like any other storytelling sites (Webtoon, Tapas, Web Comics, even Wattpad). In other words, it's just a platform. Know your target audience, their age range, their likes and dislikes, the tropes and media they are familiar with. Plan out your comic, have all the plot and point out any possible plot holes out of your comic. Practice storyboarding and composition and make concept arts and character sheets for your comic. Once you're ready, go out there and post. Good luck! 
