The Customer Journey is a strategic tool that helps you to keep the users and stakeholders at the center of design decisions, highlighting difficulties (the pain points) and opportunities for the organisation to create a better experience and an effective service. While using it, you will have to individualise the stakeholders you will be designing for and map out the main phases of their journey throughout the service. Then, you will be invited to draw sketches for each phase and identify the needs of the user or stakeholder and define the touchpoints of interaction with the service/system.

Use this tool as a prospective tool to better envision the experience of your system.
You can also do storyboards to better visualize the experience.
Stakeholder journeys and blueprints are closely connecting. Be smart on the way to map your phases.