Yes, however it may not be necessary. Any users created in AssociationSphere that are later deleted, will still show on your list of users, but shown as a deleted user. You may want to consider creating a volunteer user that you can utilize for event help. Many organization will create email addresses like "vol1@yournonprofit.org" or "temp@yournonprofit.org" and use those addresses for volunteer help login.
The same username and password can be logged into AssociationSphere from different devices, so several volunteers can share the same login.
If you will be using the mobile app, be sure to grant this user mobile access as shown below. Most volunteers do not need admin access and you can also limit which modules they can view or access using the View/Edit menu once the user is created. To learn more about user management, see this video: https://vimeo.com/855091980 (password: AS2021).