In the Editor, while editing a Step, you can obtain the direct link for the specific Step you are working on. When accessed, this URL will start the Journey from that specific step.
You need to click the "Get Link" in the bottom left corner of the Content tab.
Be aware of the fact that Visibility Rules are applied when a user opens a shared link.This means that some Journeys are visible only under some conditions. If a user follows a link to a Journey that is hidden in accordance with some applicable rule(s), the system will display a notification.