In general you should gather as much information as possible to get to know the German world of work. You can also do this online – if you know some English – via the website berufe.tv
You can watch films on many vocational training courses there.
Approach others – ask a lot of questions
Speak to friends and relatives who have already lived and worked for some time here in Germany. Perhaps they already have experience that could help you. Make inquiries too of employers about internship positions in order to get to know professions.
The employment agency ("Agentur für Arbeit") and job centre ("Jobcenter") will provide you with advice and support in your professional orientation.