How to set up a crypto brokerage?

As a financial professional interested in cryptocurrency, I'm wondering about the process of setting up a crypto brokerage. Could you walk me through the key steps? Firstly, what are the regulatory requirements I need to be aware of in order to operate legally? Secondly, how do I determine the most suitable business model for my brokerage, considering the various options available? Additionally, what are the essential technological components required to ensure a secure and efficient trading platform? Furthermore, how do I attract and retain clients in this competitive market? Lastly, what are some common challenges I may face and how can I overcome them? I'm eager to learn more about this exciting field and appreciate your insights.