How to buy BNB instantly?

Could you please elaborate on the process for acquiring Binance Coin (BNB) in an expedited manner? I'm specifically interested in methods that provide immediate transaction finality. What platforms or exchanges would you recommend for a swift and secure purchase? Additionally, what steps should I take to ensure the safety of my funds and personal information throughout the transaction? Is there a specific time of day or market conditions that would be optimal for purchasing BNB instantly? Any guidance or best practices you could provide would be greatly appreciated.