If I burn 500 calories and eat 500 calories less, does that mean I just burned 1000 calories?
no, it means you burnt 500, and skipped 500, which means your body will prolly hoard more the next time ya eat, congrats!
No, it just means you burn more calories than you ate. Which is what you want to do.
If you burn 500 calories and eat 500 less, it does not mean you have burn 1000 calories. However, you will not have the 500 calories to burn meaning you will burn more calories. I would advise you to keep exercising to keep your calorie level down