i did was make illustrations of my life in my journal. i would write about what happened to me for that day, and then draw a picture of it. my pictures were horrible, but they were illustrations from my life. drawing scenes of situations from your life, be it from your imagination or what you observe, helps you to build some must have skills for creating comics.
if you want to get more into writing and drawing, i recommend that you do the writing exercises from the 4 things i did to get started with writing fiction post, and then draw scenes from what you write.
...and go beyond the types of 