Strat with mild exercise like walking or jogging , play a sport like tennis or basketball or swim later you can build your stamina .. good luck.
If not you might be home schooled within an organization thing. They usually have sports with other kids and you can sign up.
I used to be apart of a home schooling thing christianheritagecorona.com.
When your not learning say at recess or after "school" go for a bike ride before you go to bed to 10 push ups and 10 sit ups that will be excercising or ask a friend.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.