Process is: People who sign up via the website are assumed to be totally new to anything and everything edgeryders, maybe never had contact with any of us or know at all how this works. And may not have clear ideas about what event they might want to go to.
People who drop in to the individual session/event description on the platform (like yours) are assumed to be interested in participating in that event.
In both cases they will need to create an account and introduce themselves as well as pick some tasks to help with in order to secure their tickets. The difference is the order in which they do it. But, if this seems confusing we can and ought to simplify it - which I think is being discussed here: Onboarding form proposals