What are the stages of cryptocurrency purchasing?

As a novice in the world of cryptocurrency, I'm curious to understand the fundamental steps involved in purchasing digital currencies. Could you break down the process into distinct stages? I'm particularly interested in knowing the initial setup requirements, selecting a suitable exchange platform, determining the type of cryptocurrency to invest in, executing the actual purchase, and lastly, the security measures I should take to safeguard my digital assets. Each stage holds its own complexities and nuances, so a thorough explanation would be greatly appreciated.