To log in to MetaMask, follow these steps:

Install the MetaMask extension for your preferred web browser (Chrome, Firefox, or Brave) from the official MetaMask website at metamask.io.
Once installed, click on the MetaMask extension icon in your browser toolbar to open the MetaMask pop-up window.
If you already have a MetaMask account, click on the "Restore from seed phrase" option. If you don't have an account, you can click on "Create a Wallet" to set up a new MetaMask wallet.
Enter your 12-word seed phrase or import your existing seed phrase if you're restoring your wallet.
Create a strong password to encrypt your MetaMask wallet locally on your device, and confirm the password.
Follow the on-screen instructions to complete the setup process.
Once logged in, you should see your MetaMask wallet with your account balance and transaction history.
Remember to keep your seed phrase and password secure as they are essential for accessing and backing up your MetaMask wallet.