Simply put, journeys are stories while activities are journaling subjects.
A journey has a start and end while an activity doesn't.
Some good example of journeys: First year at college, The Piano class, Trip to Hawaii, Learn how to swim,...
Some good example of activities: Reading book, Watching movies, Workout, Gratitude journal, Summarize my week,...
For more information: Organizing
While entries are great for capturing your thought, notes will be useful for quickly capture your ideas, lists, save important information for planning.
Use note for lists or references that you access quickly in the future.
For example, you can use notes for: capturing thought while reading a book, save important information for a journey, personal information for a person, reading list, ...