This reads like as a eu-citizen you get support: https://www.amsterdam.nl/en/work-income/apply-for-benefit/ (should be similiar for other cities) - there is brexit but there is a transition period until the end of 2020: https://www.government.nl/topics/brexit/question-and-answer/...

I would suggest to look for organisations that support you while dealing with the paper stuff but from a quick glance this might be useful (at least health insurance, monthly money, maybe access to some kind of paid training program that fit's your needs).