At the start you can only sign up for one role, this is the one you think you are the most suited to. Once you have gotten a taster of the platform, you can look at working in other roles.
For a new role, you will have to come in for an interview so that we can make sure your skills are up to our expectations required for the role. However, if your current role is similar e.g. Bartender and Barback, you will not be asked to attend an interview.