You can rename the tags you've created, merge tags, or delete them. Here's how:

• Rename tags:
  Go to 'Settings' > Select 'Tags' > Perform a right swipe on the desired tag > Select 'Rename Tag' > Assign a new name
• Merge tags:
  Go to 'Settings' > Select 'Tags' > Tap 'Edit' at the top right > Choose the desired tags > Select 'Merge' > Choose the tag that should be kept > Tap 'OK'
• Delete tags:
  Go to 'Settings' > Select 'Tags' > Perform a left swipe on the desired tag > Select 'Delete' or
  Go to 'Settings' > Select 'Tags' > Tap 'Edit' at the top right > Choose the desired tag(s) > Select 'Delete'