training as a kindergarten teacher/spa teacher?

Hey, I'm currently in 9th grade and will soon be getting my secondary school diploma. I know it varies from city to city, so I'm mentioning it. I live in Hamburg and would like to know how to become a social work assistant and (maybe) a kindergarten teacher. What qualification do I need to go to vocational school, how long will I stay there, and what can I do afterward? Another plan would be to study psychology afterward, but I have absolutely no idea how it works there, and no one could really tell me. Please only reply if you're sure, like someone who actually has experience with this kind of thing. Thanks.