Beach, of course
The main purpose for coming to Varazze and the surrounding areas on the riviera is the seaside leisure. Varazze itself is perhaps not the best beach resort, since the beach is in the center and overcrowded, but maybe someone likes that? I preferred less populated the beaches in the outskirts. Many beaches are pay-beaches, with beach snack-bars, umbrellas and beds, etc.
Go snorkeling or scuba diving, there is a plenty of underwater world to explore. Some people were coming back with incredibly beautiful shells! it's especially interesting in the rocks area, on the sandy beaches not as much.
Take a walk along one of the roads above the sea, there are different elevation levels where you can stroll and enjoy the landscape views. Far in the back you can see Genova!