Finally, events and parties are allowed again! However, we still have to follow the guidelines laid out by the Dutch Government to combat COVID-19.
For all events you will have to prove upon entrance that you are either fully vaccinated, had COVID recently (within the last 6 months) or tested negative within 40 hours before the event. Proof of any of the above options can be done via the Dutch CoronaCheckApp, any other digital form (PDF of a certificate), or of course on paper.
A test to get entrance to an event can be booked via https://testenvoortoegang.org, or also via the CoronaCheckApp. Once you enter the event (after provide proof of being fully vaccinated, a negative test result not older than 40 hours, or being recovered from COVID-19 within the last 6 month) no face masks are required, nor do you have to keep to the 1.5m rule.
If you travel from abroad to an event in The Netherlands you might be required to show a negative test or even to quarantine for up to 10 days, depending on the country you stayed before. Please consult the Dutch travel advice in such a case. Also, please make sure it check, which additional rules the event you want to participate at might have.
In any case, have fun and stay safe!