How do I buy from ICO drops?

Could you please elaborate on the process of purchasing from ICO drops? As a cryptocurrency enthusiast, I'm particularly interested in understanding the steps involved in participating in such opportunities. Do I need to be registered with a specific platform? Are there any prerequisites or qualifications I should be aware of? Also, could you provide insights on how to determine the legitimacy and potential of a given ICO drop? I'm eager to expand my portfolio but want to ensure I'm making informed decisions.