Do I need a credit card for a good credit score?

Strictly speaking, no. A credit card is not the only way to borrow money. However, it's the easiest way to start building a credit history, and can open doors if you give it the same respect that you do with your cash. Spend only what you can pay back that month, and never let the fact you have a card influence a buying decision.

No. But it's probably the fastest way to increase your credit score. You can take out loans but then you'll be spending more money.

You debit card does nothing to build your credit.

You need loans and/or credit cards to build credit. You will need a couple years of good payment history on loans or credit cards to see decent credit.

Credit cards are the easiest way to build credit. Get a card, use it for regular purchases, and pay the statement balance in full every month. That builds credit and avoids interest. You don't need to charge a lot or carry balances.

If you want a credit history... then yes, you will need a credit card. Your bank account transactions and that includes what you do with your debit card... does not count.

Part of your credit score is based on your payment history, and part is based on your available credit. So if you've never had a credit card or line of credit, then your score isn't great.

Why not get a credit card and treat it like a debit card?
Or if you're really worried about your willpower, then don't put the card in your wallet. Set up your phone bill to automatically charge that card every month, then hide the physical card.