One account, one side of the desk.
A student account searches and books. A hostel account lists a hostel and manages beds. The choice decides which product you get, and it cannot be swapped later — so it is asked once, first, in plain words.
Already registered by a hostel?
If you already live in a hostel that uses GetMeBed, ask them for your login instead of creating a second account — your stay and receipts are already attached to it.