Been to Jersey I think 3 times, once with a load of mates and twice with my family.
It’s best if the weather’s good, what with the excellent beaches, although there’s loads to do in general.
German Underground Hospital’s well worth a visit, as are several of the other WWII bunkers around the island.
There’s thte Zoo, Jersey Pottery, St Helier for shopping, the castle, Jersey Pearl, a big crazy golf place, loads of restaurants/cafe’s, walk out to the lighthouse, tons of scenic locations & walks.
Greve de Lecq is a nice beach/bay, bit quieter than others, sheltered.
For evening stroll/meal St Aubins bay (nr the castle) was pretty nice.