Begin by thinking about your target audience. What kind of story would they enjoy? Then, create compelling characters with distinct personalities. And don't forget to work on the art style - it should match the tone of your comic.
To start off a comic, start with a clear concept. Decide on the genre, characters, and the main plot. Also, plan out the layout and style of your panels. It helps to have a storyboard to guide you.
First, you need a great idea. Something unique and interesting that will catch people's attention. Then, do some rough sketches to visualize your story.