Yes, the Austrian Embassy should be the ones to advise but you can also try Innovations Salzburg as they are also State funded and represent the Salzburg region. Their advice should be free https://www.itg-salzburg.at/en/internationalization/welcome-service However we have not had too much success with them. The British Embassy in Vienna also has a Trade Team who may be able to assist – https://www.gov.uk/world/organisations/british-embassy-vienna#contact-us . You could also join the Facebook Group for Self Employed in Austria – https://www.facebook.com/groups/SelfEmployedAT