Sprachportal is a fee online resource also offering free live lectures
https://sprachportal.at/en/mein-sprachportal-at-a-glance
Language Reactor is an online tool for simultaneous subtitle translation with vocabulary trainer
https://www.languagereactor.com/
VHS is a provider for general education in Austria and offers semester courses
https://www.vhs.at/de/k/sprachen/deutschkurse-daz
Sprachzentum of Universität Wien is a provider for courses in different formats
https://sprachenzentrum.univie.ac.at/de/deutschkurse-1
International Office of TU Wien cooperates with innes for courses in different formats for Erasmus students
https://www.tuwien.at/en/studies/international/incoming-exchange-students/erasmus-study-joint-study/german-courses-at-tu-wien
Language Cafés and language exchange services offer opportunities to practice with others, often they are free of charge
https://wienxtra.at/informationen/infos-a-z/info/sprachcafes/