Site Templates

If you don't see templates at sites.google.com/new, click the main menu at the top left (the three vertical lines in the upper left-hand corner) 

The list of languages templates are currently available in is here: https://support.google.com/sites/answer/9718080.
They are actively working on expanding the supported languages.

Templates are available in these languages

They are actively working on expanding the supported languages, and Polish in particular should be available at some point in early 2021.