templates for labels

Yes. The print panel of the Contacts application gives you access to Avery labels and provided you have imported contacts from Numbers or Excel into a new Contacts Group, you can print labels from the contacts in that group. Simpler than fooling with Pages which has no built-in Mail/Data merge capability.

Or, from Avery templates (if in the U.S.) for Pages. Here are Avery's templates for Address & Shipping labels. Click on the WePrint link for the preferred labels, and on the subsequent page will be a clearly identifiable Pages template download.

Open that Avery Pages template in Pages, and then save it as a new template giving it the template name (e.g. Avery_5150).

With Pages, you will either need to build a single label, and replicate it within the template if all the same, or endure the effort to create different labels to fill the sheet. If you are not bashful with code, perhaps this can be simplified by recent posts featuring programmatical Pages Mail merge solutions. Here, and here.