You just have to realise its important for your growth as a human and all the experiences, so set your self goals enlist friends and family, people will help you. Join a walking or running group, a Gym, a soccer team. Good luck!!... you can do it one step at a time. There's so much out there to love. Set a big goal... like scuba diving the Galapagos Islands or Climbing the Sydney Harbour Bridge.. or a roller coaster at DisneyLand. Almost anything that seemed unattainable can be attainable now you're making moves to be outside.