Export old sheets



I have a basic plan, so can only create up to 10 sheets. To free up space for new sheets, I'm trying to export some old sheets that I would like to keep to Google Drive. However, when I try this, I get the following message:

"Contact us for a Data Shuttle license. Eliminate tedious and error-prone copy and paste of your data into sheets. To create workflows, please contact your System Admin or contact us."

I don't have a System Admin - I am the main user who signed up for Smartsheet.

Any suggestions? Thanks