I’m not sure what the Netherlandic term for high school is, but you should have figured this out a couple of years ago with the help of your parents, teachers, etc. Do you have a job or some sort of reliable income? Are you a student at a university, if you get out of secondary school at 18? I need some more information to answer this.
Get a job and then a place of your own.
Become self-supporting and pay rent to your parents Con Talk someone into supporting you through a college career – a Masters Degree at least
@YARNLADY gives a pretty good overview of what you ought to do. Sooner or later, anyway.
As for what you’re allowed to do as an 18 year old: voting, buying beer, and hiring porn. Maybe also deciding if you want to be a donor; not sure if you need to be 18 for that [0.51].
You’ll be allowed to get a driver’s license when you hit 21, I believe.
As for what you need to do: not all that much. You can continue to live with your mum and dad for a few more years if it suits you, and leave the bills and your insurance and everything to them for now. I’m a 22 year old student and I still haven’t moved out or become financially independent. I live in the Netherlands too.