In order to participate in education at Utrecht University, you must register for courses per semester. You are automatically registered in all required courses in the first semester of your first year. This will be done in the orientation week by the Student Information Desk. As of the second semester, you have to register for courses yourself. You must also not forget to re-enrol in your programme each year.
Before you register for a course, check whether you meet the entry requirements. Also be aware of the registration deadlines for other faculties.