creating labels in pages, Mac OS Catalina

Avery has some blank templates in Pages document formats now, at least, for U.S. access. This would be simpler if Pages actually supported Mail merge as in the older Pages '09 v4.3. If you were making a sheet of identical labels, then it would be a single label from a Text box, that you duplicate across, group that row of labels, and then duplicate that row of labels downward.

If you have your names and addresses in a spreadsheet, you can export that as a plain-text, comma-separated-values (CSV) document, and Apple's contacts application will allow you to import those names/addresses into a new Address Group. You then select all names in that specific address group, and visit the print panel, where you can then print Avery labels from there.

My only experience is using Avery's software. You can do that online via: https://www.avery.com/software/design-and-print/

You are welcome.