The supermarket is located on the ground floor. You can also apply for a refund there. On the upper tier there are even elements of Bauer hockey uniforms, skates of this company, leather jackets, books and much more. There is a grocery department on the ground floor.
Getting from Helsinki Railway Station is 1 stop at the border of the AB zone. By the way, in the same place at the railway station, you can issue a card for 5 euros in HSL and replenish it with the required amount. I used the R direction to get to St Pasila, but the employee said that all trains stop there, because it's next from Helsinki.