Hi Jamestown,
The “sculpting” works only on polygon objects, If you use a Landscape-Primitive, this needs to be editable.
Then go into the Sculpting Interface, with the Selector in the right upper corner. See image.
If the polygon object is selected, you can already select a tool and start, perhaps some “sub-divisions” added is a good idea.
I show-case all initial steps in this one minute clip that I have recorded for you:
https://www.amazon.com/clouddrive/share/IK9jwRcgIdM7g3YdkSXz7S90R5gPaklztoxNDEcBl08?ref_=cd_share_link_copy
You can download it, if you like.
Let me know if that worked.
All the best