I want to go into nursing.

You cannot buy an apprenticeship, you must attend the courses and practical work it requires.
There were several threads about nursing apprenticeships on this forum in the past. I recommend you read those first and then come back here with more specific questions that were not already answered.

Sounds unusual that someone living in Germany for 10 years that has taken German citizenship would ask here about training. And not to discourage anyone but your profile says you trained in finance and banking, now you want to go into nursing? This is a completely different field needing knowledge in totally different areas and a totally different type of people skills. The up side is that there is currently a shortage of nurses so anyone competent should be able to find a job. The downside is that it is usually hard work, under difficult conditions and many would say underpaid for the level of stress. It certainly is not for everyone but if you think it suits you then good luck.