How do I add Brett to MetaMask?

Could you please provide me with a step-by-step guide on how to add Brett to my MetaMask wallet? I'm a bit new to this and I'm not entirely sure what steps I need to follow. Is there a specific network or protocol I need to select? Do I need to provide any personal information or credentials? Additionally, is there a cost associated with adding Brett to MetaMask? It would be helpful if you could clarify any prerequisites or things I should be aware of before proceeding. Thank you for your assistance.