How to purchase arbitrum?

Excuse me, I'm interested in learning more about purchasing Arbitrum. Could you please provide me with a step-by-step guide on how to go about it? I understand that it's a layer-two scaling solution for Ethereum, but I'm unsure of the exact process for acquiring it. Are there specific exchanges that I should use, or are there any special considerations I need to keep in mind? Your help would be greatly appreciated.