There are no tuition fees but a semester contribution of approx. 160 EUR per semester which also covers the usage of public transport in Weimar, Erfurt, Jena and local trains in nearly all of Thuringia.
Further information on the semester contribution are available here.
As usual in any studies, additionally, some modules like the research project may require students to cover costs for excursions or a study trip (travel and overnight stay) during the semester.
The following website gives some additional information that are relevant about studying in Weimar if you come from abroad and if your application has been successful: https://www.uni-weimar.de/en/university/international/to-weimar/preparing-your-stay/