After your initial research, it is time to determine the content areas and how these will be connected: Information Architecture

https://xd.adobe.com/ideas/process/information-architecture/information-ux-architect/

What information architects do

Information architects spend their time structuring content so it’s easy for users to find what they are looking for. The more content a product has, the more significant the role of IA in the UX design process.

What is WIREFRAMING in UX
https://www.geeksforgeeks.org/techtips/what-is-information-architecture-in-ux-design/

What is IA?
https://www.interaction-design.org/literature/topics/information-architecture

What is Information Architecture(IA) in UX: Examples, Strategies, and Collaboration
https://www.thealien.design/insights/information-architecture-ux

Pull Down Menus in XD