When an organization seeks your help as Power Platform Solution Architect, you need to spend some time discovering the business, processes, needs, and customers. During discovery, you learn about the company, their current solutions, their vision for the new applications, needs, processes, and their customers or solution users.
You can learn about their business from open information sources. Also, you can ask for demos of their current applications. The best way to collect information about the project and the company's needs is to organize workshops with the targeted group of people involved in the project. Your main tool should be the question "Why?" - Why do you need this new solution? Or Why do you think the Power Platform is the best choice for your solution? These types of open- ended questions should help you to understand the company's needs and expectations. To have a firsthand view of the company's operations, ask to shadow the users of the systems. Job shadowing helps the better understanding of the user's needs and expectations.
Reference:
https://docs.microsoft.com/en-us/learn/modules/discover-customer-needs/1-introduction
https://docs.microsoft.com/en-us/learn/modules/discover-customer-needs/2-discovery
https://docs.microsoft.com/en-us/learn/modules/discover-customer-needs/3-meetings