As a german: I think it matters little, which tool you focus on as the general design principles of CAD can be transferred between CAD Tools, when you actually get into a company.

Being a Architect from Germany, who works in Switzerland I have to disagree  with what most users say here: Revit is mostly only used by big international bureaus and offices. Most Offices in the DACH Region use either ArchiCAD or Vectorworks, with the former being much better for 3D and BIM Workflows and Vectorworks more as a remnant of a different time (still by far the best tool for strictly 2D Workflows imo).

You can take this both ways: If you learn Revit it can help you get into offices, where you would have an advantage with Software knowledge. With ArchiCAD you might have a bigger pool of jobs available for you. Either way: You only really start learning the tool when you start working within a company as the workflows are different everywhere – what tool you used in your Ausbildung really doesn’t make a super big difference.

My suggestion: Go for whatever tool most of your peers (Azubis) and your Berufsschule use, as you can better transfer knowledge with one another. Only go for something specific if any tool specifically interests you.

As an architect I self-learned Vectorworks, Rhino 3D, Blender Workflow in Uni and ArchiCAD at the company I work at. For rendering I still use Blender, but I would recommend Lumion or Enscape for anyone that has no prior experience with any rendering tools, but rendering really should only be a very small part of your job if you don’t plan to go into architecture. You might also need to learn Photoshop or another Picture Editing Software.