How to buy Crypto on Robinhood?

Could you please explain the process of purchasing cryptocurrencies on Robinhood? I'm particularly interested in understanding the steps involved, from signing up for an account to actually making a purchase. Also, are there any specific requirements or limitations I should be aware of? Additionally, could you elaborate on the fees and commissions associated with buying crypto on Robinhood? Finally, how secure is the platform, and what measures does Robinhood take to protect users' funds? I appreciate your assistance in guiding me through this process.