Hi @webitc8970
For all the parts that are internationalized from static strings within the plugin, they should all be able to be acquired from setting up your install to use your language of choice. You can see the status of the plugin overall for translation at https://translate.www.ads-software.com/projects/wp-plugins/custom-post-type-ui/stable/
For example, Swedish looks to only be 55% translated, meanwhile Dutch is 100%.
In terms of the values being put in to the labels when registering your post type or taxonomy, we have yet to really find a great solution for making those translatable, as they are stored as is in the database. I know I have been trying to over the years to find a way to if anything, provide extra UI to pick the language and store the new translation separate and load appropriately, I just haven’t figured out a release-ready solution.
In terms of content in the posts or terms themselves, after having registered a post type or taxonomy, that’s more up to plugins like WPML or Loco Translate. We don’t attempt to delve into those spots.