Students with Passport from an EU country, Iceland, Norway, Liechtenstein or Switzerland don’t need to do anything before the arrival.
But as soon as the student arrives, the student must register with the local authorities if the student is going to stay in Spain for more than 3 months. Before this you will receive the NIE number, which is required, i.e. to open a bank account or use the Spanish National Health Service.
For the rest of the students you must apply for a Student Visa.