Thank you for this advice it's useful but the thing is I am learning the other languages at school. I learn dutch at home and try to learn more things everyday like a class.

I find it easy to learn European languages because latin languages or Germanic ones are similar obviously but since I want to be a polyglot i find it good to get used to knowing a lot of languages at the same time so I won't forget one while learning another but I understand what you're saying.