How to buy Ethereum ETH?

Could you please elaborate on the process of purchasing Ethereum (ETH)? I'm interested in understanding the steps involved from start to finish. What are the prerequisites I need to fulfill? Do I need to set up a crypto wallet first? Where can I find a reliable exchange to buy ETH? Are there any fees or commissions I should be aware of? Also, is there a specific time or day when buying ETH is more advantageous? I'd appreciate it if you could provide a detailed breakdown of the entire process. Thank you!