I'd reccomend doing a lap of the lake (there are some other geocaches for you to find as well!) but there are also plenty of parking spots around the lake if you just want to head straight to the cache and back again.
Interestingly, Lake Claremont marks the border between the Quindalup and Spearwood dune systems, meaning there are different soil types on the west and east sides. The spearwood dune system (on the eastern side) contains Tamala limestone - the same stuff as the rock formations at The Pinnacles. The primary compound in this limestone is calcium carbonate, which makes the water of Lake Claremont somewhat basic (high pH). Regardless, the lake continues to support a high degree of biodiversity like all good wetlands should. :)
The cache isn't close to the water. Not too far from the road, in a grassy area. Don't forget a pen!