Commit yourself to taking a walk every morning or doing some type of activity. The more we stay still, the lack to want to do anything productive continues. You'll increase your endorphins and feel better, too.
Get your parents to sign you up for some kind of class or activity. Then if you're scheduled for something you're likely to follow through. If you meet people, maybe that'll motivate you more to get out and see them.
get involved, get youself motivated, start going for walks, eat foods that give you energy(naturualy) if you younger than 18 sign up for this(parents) http://www.kidsbowlfree.com/ help out around the house, volunteer.