Normally, you edit the title of a note in the title bar region of the note. The title bar is located at the top of the note. If the title bar is hidden when you create a note, SOHO Notes will automatically use the first line of text from the note as the title.
If you're unable to edit the title of a note, it might be because the note title bar has been turned OFF (it's ON by default). Here's how to turn it ON:
1) Choose View > Show Note Title Bar