As with all writing, comics need a script. The plot must lead from point a to point b and must be illustrated. Read several and find that the plot starts on page one and continues throughout several pages. The trick to continuing the story is to have a point to stop the action of the story at a critical moment in order to wait until the next installment. This techniques is known as the cliffhanger.
You need to have a hero, a villain, and at least one character to kill off. This kill character must move the plot along without being central to the theme. Of course you need to have drawing skills!
Your character must be simple to draw and recognisable in many different angles as your unique character. Your villain must be the same. Minor characters can be generic, but need to be slightly different for interest. In cartooning, the backgrounds are pretty much generic, with the emphasis on the character in the foreground. Look at the classic X-men comics, cartoon strips and movie cartoon for tips on how to plot your characters, move your action, and resolve your story. The Roadrunner cartoons are excellent for this purpose.