The doctor told me..

So I went to the doctors a while back and he said I had to lose at least a pound a week, I'm 17 and over 200Ibs but I'm like 6' tall (not exactly sure but I'm pretty up there) I need lots of tips on the best way to start and actually lose a pound a week please, I don't have a car or the money to go to the gym either. Idk where to begin.