If the label stationery provider doesn't have a template or instructions
suitable for Word,

a. Is Word you only option (or your most familiar option), or is there some
other software (perhaps from the label provider) that could help you here?
b. as far as Word is concerned, Word label layouts are in essence Word
tables with one cell per printable label. The difficulty is determining what
the size of those cells should be. I would probably start with an existing
label layout (because that kind of table already has fixed-height rows
defined) and try to adjust the table dimensions to suit  - perhaps you have
2 different label shapes per row?

I doubt if that answers your question, but if it doesn't help at all, can
you please say
a. which version of Word you are using
b. what stationery you are using (e.g. manufacturer/serial code)
c. what size sheet the labels are on (A4? US Letter?)
d. how the labels are laid out on the page/

Peter Jamieson