There are high chances that you might have forgotten the MetaMask sign in password. But, you can easily regain access to your account or wallet either by resetting the password or by importing your wallet. But, in both cases, you will need to have access to your secret recovery phrase.The secret recovery phrase is the key to your wallet and is provided to you when you start to set up the wallet for the first time. In case you have access to this seed phrase, you will never have to worry about losing access to your wallet.