In this article, you can find what permissions are required to execute the different steps of a Journey. 

Permissions for creating a Campaign:

To create a campaign or modify an existing one, you will need following permissions under:

Setup > Campaign

Permissions required for Audience Management :

To create and manage Audience Profiles, you need following permissions under:

Audience > Audience Profile

Also to create and manage audience segments, you need permissions under:

Setup > Data Management Platform

Permissions to Create an Email Marketing Content Template:

To manage your Email Marketing Content Templates, you will require following permissions under:

Setup > Content Templates

Permissions to create assets for Journeys:

To create and manage your assets (Post asset, Omni chat template or Simple Text asset), you will require following permissions under:

Content > Media Asset

Permissions to build and execute a Journey:

To build and manage your Journeys, you will require following permissions under:

Marketing Journey > Marketing Journey