I can't pick a specific line, but some of my worst writing includes:
1) In elementary school, one of my assignments was to write a diary entry as a historical figure. I had no clue how to do research properly, and was still learning how to write. So my only source was a historical fiction book already written as if Cleopatra had kept a diary, and I (poorly) copied the over-dramatic theatrical writing style.
2) I had to write a short script based on Romeo and Juliet for a high school project. I wasn't the best at capturing emotions in writing or understanding what a normal human reaction would be in some situations, so major, tragic things would happen, and then I'd just have the other characters be like "Oh, bummer. anyway..."
3) Basically the entire plot of a comic I worked on in middle school and high school. So many plot holes that I clumsily tried to cover up...