Education Consultancy Service in Germany

I am going to move to Germany (Dusseldorf) soon with my 9 years old kid, who does not know German language. Now I need support how to build education route for my kid from now on not to impact University exams in the future. I know they have Gymnasium education system criteria to enter University which needs to have mandatary German exam at 5th grade. Which is not feasible for my kid who is in 3rd grade end now.

I need a consultancy service from an Education Expert for Germany how to handle this case and to be prepared to University in the future too.