Whatever you were learning, write about it. Since this is post is in middle school, your teacher probably expects atleast half a page to be written in. Write about whatever was asked to be written in the entry. If you're reading a book for class, it may need to be a summary of what you read in the book. If you had an assignment, it's probably about the assignment. "Journal entry" means to write in your notebook, so this wasn't very clear what you need help with, ask a classmate about what assignment needs to be written about
If a director wanted to make the story less depressing, they could cut out the ending in which they both commit suicide. This would greatly affect the message of the play. However, I am not sure if this is what you need.
I think its asking for what scenes in Romeo and Juliet and unnecessary but really, if you cut any scenes it will still affect the relationship between the characters as the audience will not seen them develop throughout the show