And I'm not a sporty person Because Im on the computer all day.
and I hate sports
And I don't want to study or work.
What to do outside?
Go to the public library. Or if you have a university nearby, maybe you can sit there. Most libraries also have computers where you can research. OK, no social networks or games, though.
Your parents simply want you to have some fresh air. If you live in a good warm climate, maybe you can sit just outside the window with your computer and keyboard facing outside. Then you can sit on a high chair and do your pc stuff from outside.
If you do not want to study or work how on earth do you imagine you will be able to support yourself when your parents are no longer there.
You need do go outside, if you do not want to make friends get a dog and take a walk with it. Bring your phone and play games in park.
Go for a walk in the park or around the neighborhood. You may not want to study or work, but sooner or later you're going to need to be able to support yourself. Listen to your parents.
Buy a tablet PC and go to the park. Maybe you'll meet a nice girl there or maybe even a bad girl. Bring a frisbee to since you don't need to be too athletic for to play frisbee and it's good excercise and fun.
Move your computer outside..
Go for a bike ride.