It is compulsory to register at the municipality in the Netherlands (In Dutch: “inchrijven bij de Gemeente”) and in the same appointment you will complete the application for your BSN number.
For this appointment you will need your Unabridged Birth Certificate & Apostille, Marriage Certificate & Apostille (if applicable), proof of residence (rental contract), proof of ID (passport) and employment contract.
This can be tricky if you are planning on staying in temporary accommodation upon arrival because you need an official address in order to register at the municipality. When booking your accommodation, ask for permission or whether it is indeed possible for you to use the address to register. Some AirBNB locations to allow this for example.
Should you decide to live or already have accommodation in Amsterdam, then you don’t have to go directly to the IND nor apply for the BSN number at the gemeente, but then you can visit the Expat centre in Amsterdam. In this one meeting you will report to the IND, register with the Gemeente as well as obtain an BSN Number. You will have to provide proof of residence on this appointment in the Amsterdam gemeente: http://www.iamsterdam.com/en/our-network/in-amsterdam.
For additional information and assistance in the Utrecht area, you can visit this page: https://www.utrecht.nl/city-of-utrecht/living/expat-center/
Should you succeed in finding permanent accommodation very quickly, then you can go directly to the Gemeente where you will be staying and register there.