Where is BNB sold?

Excuse me, I have a question regarding the cryptocurrency market. Could you please tell me where exactly I can purchase BNB? I've heard a lot about its popularity and potential for growth, but I'm not sure which platforms offer it for trading. Is there a specific exchange or marketplace where BNB is commonly sold? Also, are there any specific requirements or steps I need to follow to buy it? I'm quite new to this field, so any guidance would be greatly appreciated. Thank you in advance for your assistance.