Open the Files app
Tap Browse
Tap Downloads under Locations
Tap Select
Choose the files you want to delete
Tap the Trash icon
Open the Photos app if the download is a photo or video
Select the item
Tap the Trash icon
Open the Music app if the download is a song
Go to Library
Find the downloaded song
Tap and hold it
Tap Remove Download
Open the TV app if the download is a movie or show
Go to Library
Find the downloaded item
Tap the More button
Tap Remove Download
Open the Podcasts app if the download is a podcast
Go to Library
Find the downloaded episode
Tap the More button
Tap Remove Download
Open Safari if you want to clear downloaded files from the browser
Tap the Downloads icon
Delete the downloaded file from Files if it is still saved there
Empty Recently Deleted in Photos if needed
Empty Recently Deleted in Files if needed