There are two ways to get to the email signature settings in Outlook:
- In the top left of Outlook click File > Options (bottom left)> Mail (left pane) > Signatures button (right pane in the Compose Messages section)
- Create a new email and click the Signatures button. Depending on your view it will look similar to one of the below two screen shots. Here you can manually choose the signature for this email or go into Signatures to edit your signatures or set the default one to use.