I wouldn't know what a better page would be. Maybe the Main Page?

For comparison: on Wikidata and Wikipedia, there is simply no "Cancel" option, only a "Create" respectively "Publish" button.

In order to stop that action, you simply leave the page, click another link, or close the page.

“Cancel” simply cancels the edits. This flips you straight back into “read” mode on Wikipedia and Wikidata. On Wikifunctions, for existing functions, we get a “Discard Edits” confirmation dialogue first, then we are returned to the page in “read” mode. We cannot be consistent with this for a page that does not exist, but a reasonable expectation after such a dialogue prompt is that the edits are discarded and you are left on the page as it was before any edit. Anything else would imply a third option in the “Discard Edits” dialogue, which is effectively “Back”.