There are several organisations or associations for different mother tongues. Please check out the local services. In addition, there are courses at the adult education centre.
https://www.vhs-th.de/vhs-in-thueringen/fachbereiche/sprachen/
https://www.vhs-th.de/fileadmin/redaktion/vhs_in_thueringen/Fachbereiche/sprachenatlas/Sprachenatlas__2016.pdf