Hey Rhhhee!
The only side task available at the start of chapter 14 is hanging out with staff (at the moment Luke is the only one who has some scenes available). As the game goes along you get additional tasks with some of the other characters.
If the task text is blue, that means that the guest is either unavailable or busy with a team (either R&D or Exploration). If you go to the manage teams menu and move Luke to unassigned, the task will become available, you just need to click it (or tap it, since you're on mobile) and select Luke.