How to buy an ETH username?

Could you elaborate on the process of acquiring an ETH username? I've heard it involves blockchain technology and cryptocurrencies, but I'm not entirely sure how to proceed. Is there a specific platform or marketplace where I can find and purchase such usernames? Do I need to have a certain amount of Ethereum coins in my wallet? Additionally, are there any security measures I should take to ensure the safe transfer of funds and ownership of the username? I'm keen on exploring this opportunity but want to ensure I understand the entire process thoroughly before making any transactions.