How do I buy core from MetaMask?

How do I purchase Core tokens using MetaMask? Could you please provide a step-by-step guide? I'm interested in adding this cryptocurrency to my portfolio but I'm not quite sure how to proceed. Could you also clarify if there are any specific fees or requirements I need to be aware of before making the purchase? I'd appreciate any additional advice or information you can provide to help me navigate this process smoothly. Thank you for your assistance.