You can book an appointment for career guidance/counselling on phone at https://karriere.oslo.no/. Then a Career Counsellor will call you at the time you booked for the guidance.
You can book an appointment for an admission interview for Norwegian courses and grunnskole by filling in this form. (Use Chrome!) Then you can have a registration/admission interview on phone/internet. After you have booked the appointment, you will receive a confirmation via SMS, and a consultant from the Service Centre will call you. Then a consultant from the Service Centre will call you when you have the appointment.
These are temporary arrangements as long as the Centre is closed due to the risk of corona infection.