If you're totally new to comics, make some one-off pages so you can experiment with what you're good at and what you like to draw before locking yourself into a larger project.
I start with characters and character design. You need to have a decent design and a good idea of what you're drawing before you get into it. I also do some setting design and a drawing or two of the characters in the setting to make sure it's working well.
Once you have your characters and setting, next is the writing process. I write out a list of important events and then I do all of my writing process in the thumbnail stage so that I can plot out the visuals and story beats together. This process is the most variable between creators though so just do what works for you. If a typed and formatted script is what works, then do that.
At that point, you're ready to do your actual comic pages - sketch, ink, color/shading, lettering. It's just production from then on.
At the end is posting, marketing, publication, and all those other unavoidable business bits.
