thanks for reaching out at wefugees.
To start with the formal requirements: You need a contract from the organisation which offered you an apprenticeship and take it to the immigration authority together with your application for a visa called "Allgemeine Ausbildungsduldung" (§ 60c Abs. 1 Satz 1 Nr. 2 Aufenthaltsgesetz). To obtain this document, your identity has to be clarified (via passport). Of course, you shouldn't have fines (or at least fines above 50/90 daily rates).
Second, the language requirements: You need at least a B1-level to start the training, depending on the profession you want to learn even more (B2 for nurses). You won't be able to pass the theoretical parts of exams if your German isn't good enough, Some organisations/schools even require a B2-certificate. You will find this Information on the homepages of some of the schools. It is also recommendable to submit certificates of your educational background, e.g. nurses as a rule need a intermediate school-leaving qualification, hotel managers can start with a basic secondary school certificate.
For hotel management there is no formal regulation of language requirements, but you have to be extremely communicative and create a convincing first impression when you get the job interview.
Please feel free to contact me again. My name is Christine and I would be happy to answer your further questions. In case you need a confidential consultation you can also write me at mbeon, which provides advice for adult immigrants in Germany via an app. Download the app at Google Play or App Store and get in touch with me or 160 other migration advisors. It's free of charge, anonymous, data secure and you can get advice in 15 different languages. Find more information here: www.mbeon.de.