I don't believe in limiting your horizons by your age. So you can read any books you want, but this depends on your interests. If you're into YA contemporary, or Chick Literature, try reading Rainbow Rowell (Eleanor and Park, Attachments, Fangirl), David Levithan (Every Day, How They Met, etc.), John Green (The Fault in Our Stars, Abundance of Katherines, etc.) and COLLEEN HOOVER (I guarantee awesomeness from this very bright author).)) But if you want adventure, you with Rick Riordan (he's all about Greek and Egyptian mythologies).