Don't worry about it being worth documenting, it is rarely the goal for journaling to document what happened accurately. It is more about discovering your thought and emotional patterns. Sometimes it can be nice to see how they have changed over time.

I write for myself with the primary goal to readjust what I know are irrational thoughts and emotions. The effect is surprisingly good, I have for example never had fewer ruminating thoughts than now. If you need a drill to get you started try gratuity journaling ; find three things to be grateful for each day.