Do I need to back up my keys?

Yes!

Private keys are stored encrypted in local storage. Even if you never forget your password, local storage of browsers can get cleared automatically. Your computer can crash or fail in a myriad of ways!

You MUST store your keys! No one but you can guarantee they can be restored. The preferred method is a cold wallet or paper wallet.

If you generate an account in MetaMask it's derived from your Mnemonic. If you store your Mnemonic phrase you can generate the same private key again. That's why generating an account in MetaMask is the preferred way to generate an account.

After generating an account use this guide to import it into Pirate Quester: Creating an account