Editing Emails
All email and text templates that go to CONTACTS can be reviewed and edited in Marketing > Snippets
They are numbered to correspond to the Actions in the Workflows.
Who Emails and Texts to Contacts are "From"
Emails in most stages are "from" the host. The wording of the emails make it sound like it's from the host as well.
If you'd rather they come from someone else, change only the "Signature Line" custom values - don't change the Host Name or it will mess up other content.
Alternatively, you can change the Email templates, but be sure to go in and change the Email actions within the workflows. The "From Email" and "From Name" are also set to the Host's name and email address.
Internal Notifications
Emails, Texts, Tasks, and App Notifications that go to the host and assigned users are edited within their respective Workflows.