You can either rename your created tags, merge tags, or delete them.

Just follow these steps:

1. Rename tags

'Settings' > 'Categories & Tags' >'Swipe left to the desired tag' > 'Rename' > 'Assign a new name'

2. Merge tags 

'Settings' > 'Categories & Tags' > 'Edit' > 'Select desired tags'> 'Merge tags'> 'Select the tag you want to keep'

3. Delete Tags

'Settings' > 'Categories & Tags' > 'Swipe left to the desired tag' > 'Delete'

or 

'Settings' > 'Categories & Tags' > 'Edit' > 'select desired tag(s)'> 'delete'