I ate pizza that was on a paper plate cooked in microwave is this gonna cause cancer im worried?

Generally speaking, it's safe to use a paper plate in the microwave. For the safest results, stick with plain white paper plates. Printed, decorated or non-white paper plates may increase the odds of fire, or they may leach chemicals into the food being heated. You should not worry much, I do that all the time.

No, this one episode is not going to cause you cancer. You can reduce your risk of cancer by adopting healthy habits: Eat a mostly vegetarian diet, avoid alcohol, tobacco and street drugs, avoid excessive exposure to sun, get HPV vaccine, exercise 30 minutes each day, drink enough water so your urine is mostly colorless.