For labels you print yourself, see the Avery Blank Labels:
https://www.avery.com/category/shape/all/
See the Avery Retail Packaged Labels:
https://www.avery.com/products/labels/usage/all-labels
If you want Avery to print your labels for you, visit WePrint:
https://www.avery.com/custom-printing/labels/
Avery WePrint Roll Labels offer custom shapes and sizes:
https://www.avery.com/custom-printing/labels/calculator/rolls