Kids start primary school (Grundschule) at 6. it’s not uncommon for a child to be put back until 7. Children have a school-readiness test before being accepted where they have to say certain sounds, draw a person, and their fine and gross motor skills are tested. School is compulsory, in our case has a variable start time of either 07:45 or 08:30, a variable end time of either 12:20 or 13:15, and daily compulsory homework.
There is non-compulsory Kindergarten from age 3 (with a crèche from 1). Quite a few kids go 3 hours a day from 9-12. Longer hours are available. There are no letters taught before school and you as a parent are strongly discouraged from teaching your child the alphabet. Focus is on fine and gross motor skills and oral language skills.
From age 10-11 children go on to one of three types of secondary school. Hauptschule is upto age 15, Realschule until 16 and Gymnasium (grammar school) upto 18, although there are concrete moves to reraise the age to 19 in some parts of Germany. Schooling is managed on a state level and Germany is divided into 16 states. It’s very difficult to move between states once you‘re a teenager as there are recognised differences between the state education systems. I know of two sisters who had to go down a year when their family moved.
After leaving school, Gymnasium kids will probably go on to university. Unis are seen as broadly the same as each other, you tend to go to your local one.
The other school leavers go onto a 2-3 year traineeship at a company. This may be a retail company, it may be a corporate environment, a bank, or a trade. It could be a nursing home or a Kindergarten. The company employs you during the traineeship, but wages are not enough to self-support. Once you have finished the company takes you on full-time and you have earned the right to call yourself by your job (in Germany you say what you are, not what you do). It’s almost impossible to get a job without at least a traineeship and equally difficult to change jobs without retraining.