You can turn it off easily enough though it will still show as running in task manager because its part of windows search from what i read.
How to Enable or Disable Cortana in Windows 10 June 2018
https://www.tenforums.com/tutorials/...dows-10-a.html
How to Disable Cortana in Windows 10
by Chris Hoffman on August 2nd, 2016
https://www.howtogeek.com/265027/how...in-windows-10/