How to buy Crypto on webull?

Could you please elaborate on the process of purchasing cryptocurrency on Webull? I'm particularly interested in understanding the steps involved, from signing up for an account to successfully making a purchase. Also, are there any specific requirements or limitations I should be aware of before getting started? Additionally, could you provide some insights on the security measures Webull employs to protect its users' transactions and funds? Lastly, are there any fees or commissions associated with buying crypto on Webull? Thank you for your assistance.