In the historic center and the old port, but not only, you will find many bars and pubs to enjoy an aperitif before dinner or to end the evening. From intimate and reserved corners to more spacious locations even with DJ sets you can choose according to the mood of your evening.
You will find an extensive list in the link below and I leave you three suggestions of places that I know directly, in the vicinity of my vacation homes: Il Cavaturaccioli is a small and cozy place in a small square behind Piazza Campetto, really delicious, La Goletta Sea Side , at the Old Port overlooking the landing of the many Yatch, is a multifaceted place also suitable for dinner or after dinner with DJ sets and Rebus , a new place to the right of the Aquarium, with such an atmosphere that you will not feel like you are in the city.