Solution - Go to Settings -> Home -> Enable Shortcuts -> Go to a new tab -> Google will be pinned by default, hover over the Google icon -> Click on the 3 dots menu -> Unpin
Try removing Google from your search engines. If you still want it you can re-add it from search results (click address bar, a new search icon with a + should appear at the bottom) or Mycroft.
Also consider removing/dismissing Google from the new tab page. If you have disabled the option showing your most visited sites, enable it temporarily to remove Google and untick the "sponsored" option in the new tab cog icon on the top right.