How do I fund arbitrum on MetaMask?

Excuse me, could you possibly explain the process of funding Arbitrum on MetaMask? I'm relatively new to this space and I'm a bit confused about the steps I need to take. I've heard that Arbitrum is a great way to enjoy faster and cheaper transactions, but I'm not sure how to get started. Could you guide me through the process, perhaps highlighting any potential pitfalls or important considerations I should keep in mind?