Is there a way to create hills and valleys?

Hey There! Im new to sketchup and am still working on my first model. I have another one coming up that I need to design but the house Im trying to recreate is on a large hill. I have no idea how to create changes in landscape. Is there any way to make hills using this software?

Unfortunately SketchUp web based lacks the option to use extentions.
You may want to doawnload SketchUp 2017 Make (the desktop version of a former SketchUp version) which allows you to install extensions. Itself comes with some tools to create and shape a mesh, the Sandbox tools.

SketchUp 2017 Make is free but not for commercial work!