The beach near Zola is small and while it's not terrible, it's not my top choice in Kefalonia. I wouldn't make a return visit.
Parking is limited near the bar and the road leading to the beach is steep and narrow, so be cautious.
The beach is a mix of pebbles and sand with some areas that are organized for a fee of 10€ for an umbrella and 2 sunbeds. There is a free area to the right, but it's near some rocks where there were a lot of wasps. There is a bar/restaurant, shower, and toilets available. On the left side of the bar, you can access another small and unorganized beach.
There is very little shade on this beach, so bring your own umbrella.
The water wasn't very clean when we visited, with algae and foam on the surface. However, snorkeling was enjoyable, especially near the rocks on either side of the beach. Be sure to bring water shoes.