Where can you purchase BNB?

Could you please enlighten me on the various avenues available for acquiring BNB? I'm particularly interested in understanding the reliability and convenience of these platforms. Additionally, could you elaborate on the registration and verification processes involved, as well as any potential fees or limitations that might apply? It would also be helpful if you could provide insights into the security measures taken by these platforms to safeguard user funds and transactions. Finally, are there any specific recommendations you have for beginners who are looking to get started with purchasing BNB? Thank you in advance for your detailed response.