Under 18 child with GV can he go to school in german as a non international student?

Im planning to apply GV in portugal for my family and my child. I understand that we can travel through schengen without any other visa. But if my son wanted to study in german, can he used his portugal resident card /Green card in german? (It is to avoid an international school fee.)

Any similar situation or any help would be very appreciated. Thank you in advance!

Kay

Portugal GV gives you residency in Portugal. To be a resident in another country, you need to apply for residency in the country you plan to live in. I believe Germany also has a golden visa program.
This thread discuss the maximum length of stay allowed in other EU countries.

Appreciate the answer and sorry if put it on the wrong thread. German does not offer any golden visa but i will look for more information.

Thank you so much!

I searched for German golden visa and there are a lot of information online. For example, one article says
ā€œā€¦ purchase real estate worth a minimum of ā‚¬250,000 and get engaged in an ongoing regional development project, by making an additional investment of ā‚¬100,000 for five years.ā€