The Veendam is one of HALs smaller ships. Sorry to saythe nightlife onboard will likely be very slow, and will really slow down about 11:00.
This is nto a young people's or singles ship. You get a lot of older couples. Not many families either.
For music expect a string quartet, a piano bar with a singalong piano player, a "disco" with karaoake and a nightclub bar with a DJ.
It miught get somewhat hopping, but it depends on the cruise. It is certainly not the forst ship I would nominate for nightlife.