How to Orchestrate Journeys that are based on Website Behavior

Im in the process of activating several journeys that are based on known users' behavior on specific product pages. When a known contact engages with the page they will then qualify for a journey. Their engagement on the page will determine where in the journey they will enter - page visit but no engagement with tools = awareness journey stage; page engagement and use of a calculator = consideration journey stage.

My question is how do I orchestrate the audiences/journeys to ensure that a prospect does not enter multiple journeys at the same time?