You can’t rush SharePoint, it doesn’t like it. It likes things to be added in the right order so it can give you what you need. People often want to jump right into branding it. That is a going to be a costly mistake, especially in SharePoint Online which changes so often. Or they want to do all the navigation first and all the icons on the home page. You can’t start there. What are you going to link to them?
In order to get dashboards, or navigation, or home page icons – you need to get views to link them to.
To get those views, you need metadata (categories).
To get metadata, you need libraries or lists.
To get libraries or lists, you need content.
To get content, you need to understand your business process.
It will always come down to that. Work up, not down but keep the end goal in mind.