Did you know that Death Note was made by two people, not one? Tsugmi Ohba was the AUTHOR of Death Note, while Takeshi Obata was the ILLUSTRATOR. Ohba wrote all the AMAZING story in Death Note, while Obata made the stunning illustations. Really, if you want to make manga, but can't draw, I'd reccommend looking to collaborate with a willing artist.
Also, in terms of WRITING manga, PLEASE buy yourself a copy of Hirohiko Araki's "Manga in Theory and Practice: The Craft of Creating Manga". As an artist, it doesn't include very much help on DRAWING, but what few pages it has has elevated my art tremendously. Also, it explains the writing process of making manga amazinglyyy-
But I can't draw I can come up with some pretty good plots but can't make characters likeable don't know enough about what it take to make my own manga but it's one of those things i dream of /think of beside food ( ̄∇ ̄")