How do you download surveys to a PDF with basic package?

Are you wanting to download a PDF of the survey itself as described here (this looks to require at least a Standard License):

https://help.surveygizmo.com/help/print-a-paper-survey

If you are looking to download the response data via PDF:

https://help.surveygizmo.com/help/export-response-pdfs

This should be available at the Basic License.

I hope this helps clarify!