A credit card is a MUST for a traveler.
For your car you get free insurance for your car. That means you do not have to pay the car rental insurance.
For travel, if your plane crashes your family gets 100,000 in insurance.
If things go wrong, ex: you don't get the car you wanted, or a trip gets canceled the credit card will refund you. It's called protection.
Debit card offers you absolutely no benefits. Not to mention, car rental places will not accept debit cards. In case you wreck the car, or take it out for an entire month, they want to be able to charge your card. Also if you do not use credit card, you will have to put a $500 to 1,000 deposit.