If you don't wish to incur debts, a debit card may be suitable for you. It is safer than carrying cash around and the amount in your bank account is basically how much you can afford to spend!
Before you opt for a credit card, consider whether a credit card will be an occasion to spend beyond what you can afford. You may postpone paying with a credit card, but in the end you will have to pay your bill. The more you delay paying, the more interest you will be charged on any outstanding balances.
A credit card allows you to postpone payment and not incur any interest if you pay your balance in full by the due date which is written down on your statement. Look out for the "interest free" period and the interest you will be charged if you postpone payment.