I want to create address labels from my Number sheet

Use the Numbers File > Export menu to export the spreadsheet to an Excel format. See: Convert Numbers spreadsheets to PDF, Microsoft Excel, and more - Apple Support

Then use Avery Design & Print Online to create the labels. It is free and very good and will merge an Excel spreadsheet. See: https://www.avery.com/software/design-and-print/

If you want to stay all Apple you can

Import your contacts into the Contacts app:

Import contacts into Contacts on Mac - Apple Support

Print labels from the Contacts app:

Print mailing labels, envelopes, and contact lists in Contacts on Mac - Apple Support

SG