ZOB Hamburg, where ZOB means Central Bus Station, is located close to the City Center and just some…read moreminutes walking from Central Train Station. The building is quite modern, opened in 2003, it replaced the old ZOB that was build in the 50's of the last century. The ZOB consists of three buildings, called A, B and C as well as the numbered arrival/departure stops. The german word here is "Bustasche" - bus bag! Sounds bureaucratic. Anyway - just lock at the number and also check the number of your bus (in general the personal checks your ticket when you board).
The place is quite drafty and is missing a real waiting hall. just a small place is available, during opening hours. At night most people wait on the road or enter the close Kebab Kiosk oder Mc Donalds. Beause the Toilet is closed at the same time the ticket counters close, people use the places around during the night. Especially in summer you may smell it!
Just be aware of pick-pockets und don't wunder, often there are lots of homeless searching for shelter. Also drugs are sold and consumed here.
So to me, this is not a cosy place at all and you always could be happy if your bus arrives and departs as scheduled.