Buses and taxis cross the causeway to the base of the island, but often are delayed in heavy summer or weekend traffic. It's easier just to walk from the station.
There is often a small, walk-on ferry that runs back & forth between the causeway and the back of the island near the caves. It takes 5 minutes, costs about ¥ 400 and will save approximately 45 minutes walking time making it possible to see all the sights the island has to offer in one day.
Most pathways in Enoshima the island only allow foot traffic but are easily reached on foot. There are many stairs, high slopes and hills in Enoshima but it is possible to take an escalator called Enoshima Escar just to the left of the first, red torii gate. It costs ¥ 300 to go up but you'll need to walk downstairs to go back down, open 9:00~17:00.
