A journal is a more public, not-so-personal way of recording daily things happening in your life like business meetings, a to do list, keeping record of things you've done in during the day or things you'd like to do tomorrow. Goals set to do in the future and others.
Here will solely be your character's journal entry for recording things they want to do, they've done or will do but nothing relating to feelings or personal emotions. Those will be left for the diary entry.