I canceled my subscription but it is still saying that a charge is pending for that app and it is stopping me from downloading apps please help

Go here: View, change, or cancel your subscriptions - Apple Support

Note that when you cancel a subscription the cancellation happens at the end of the current subscription period. You still owe the subscription payment for the subscription that was in effect at the time you canceled. It is not retroactive. If it has only been a short while since you canceled you can contact iTunes store support and they may be able to make it retroactive.