Task: I downloaded a Zeitleiste_englisch_zum_Selbstdruck pdf file mistakenly, and I don't want this pdf file in my phone storage, so delete this file in the Files by Google app.
Steps:
Go back to the previous page 
Click on the search icon at the top right corner of the screen to search the file 
Type Zeitleiste_englisch_zum_Selbstdruck in the search bar
Click on the search icon at the bottom of the screen to view the search result
Click on the three dots icon of the Zeitleiste_englisch_zum_Selbstdruck pdf file to view the delete option
Click on the Move to Trash option to delete this pdf file 
Click on the Move 1 file to Trash button at the bottom of the screen to delete this file
Click on the Move 1 file to Trash button at the bottom of the screen to delete this file