Getting started with first product ASIN vs EAN question

I try to create my first product in sellercentral. It is a new one, so not yet cataloged in amazon. It has about 6 variants because of different sizes.

So I thought I need at least 6 different uinique EAN.

I planned to buy my EAN numbers in the german GS1-store. But now I saw, that I also can enter ASIN. After some google research I found out, that it is some Amazon ID.

Do I still need a EAN or can I also try to make a unique ASIN? This topic is so confusing for me.

I would be thankful if someone can explain to me what I really need.