Labelling a Map - nominal variable

Hi!

We don't really have enough information in your question. In particular, we don't have the data you are using to make your plot. To help us help you, could you please prepare a reproducible example (reprex) illustrating your issue? Please have a look at this guide, to see how to create one:

That being said, here is an example of how you might label polygons, using a built in dataset in the sf package.

library(sf)
library(ggplot2)

nc <- read_sf(system.file("shape/nc.shp", package = "sf"))
ggplot(nc) +
  geom_sf() +
  geom_sf_text(aes(label = NAME), size = 3)

Created on 2020-06-09 by the reprex package (v0.3.0)