If you’re looking for an ausbildung here are a few addresses where you can find positions being advertised.
If on the other hand you have already identified a company you’d like to work with, you can call them directly and ask if they have positions and/or how to go about applying to work there. www.arbeitsagentur.de check under Jobbörse
Check IHKs in your area. Just google IHK “Name of town” or “Name of Closest City”