Anything آپ want... journal entries, taking notes in class, doodling, writing stories, songs, یا poems, writing things down that آپ don't want to forget, keep track of your پسندیدہ quotes, use it to make lists, make paper airplanes... the فہرست goes on. :)
Maybe a diary, یا maybe notes for school یا for hobbies like if آپ write. یا maybe آپ can use it to draw, that's what my cousin does. Just doodle with it. Use it to do your homework on. Anything آپ want!