how do you delete apps from Apple Watch 3

Press the Digital Crown on your Apple Watch to bring up the App View.

If you're using List View, swipe left across the app you want to remove, then tap the red trash button. If you're using Grid View, tap and hold to activate jiggle mode, then tap the X in the top-left corner of the app you want to remove.

Tap Delete App to confirm.

Not all apps are available to delete.

To Free-Up Storage

For songs, see:

Remove music from Apple Watch - Apple Support

and for pictures, see the "Limit photo storage on Apple Watch section in:

Choose a photo album and manage storage on Apple Watch - Apple Support

To delete apps on your watch, see:

Delete apps from your Apple Watch - Apple Support

Also, try unpairing and pairing your watch again and restoring from the backup just created in the unpairing process. This deletes all temp and corrupted files and re-indexes the file system. This should result in no loss of data and in some cases can free a lot of storage.

Unpair and erase your Apple Watch - Apple Support

Set up your Apple Watch - Apple Support

Also see:

If you don’t have enough space to update your Apple Watch - Apple Support