When your team is added to Side’s Canva account, you’ll receive a message from Canva explaining how to keep your existing designs separate (Example). You’ll have the option to update the email address on your original account so it remains your personal workspace.
If you do not make any changes, your existing account will be brought into the Side Canva organization automatically. Your older designs will be moved into a separate workspace called “Your Name Team”, so you can still access them.