Port Campbell is the nearest big town (calling a city would be stretching the definition). I think Geelong would be the closest city.
The "hike" involves parking on the north side off the highway and walking from the parking lot under the highway to the observation points. There are some very short hikes at other sites, one down to the water where the Loch (something - not Ness, Aird maybe?) wrecked but it's fairly easy stairs, and longer trails near Cape Otway. There might be a coastal trail too but I don;t think that goes down to the shore.