Registration at the Municipality
If you want to move to the Netherlands from another country for work or study, you will have to register in the new city. You will need to collect a few documents in oder to do so, but apart from that it is pretty easy. Depending on whether you move here from within the EU or from outside of it the documents you need will vary. You should plan a few weeks for this process. It can take quite long to get an appointment at the city hall and it also takes the city a few weeks to process your request.
Remember that you will need to be registered here in order to get a bank account and a health insurance. Universities will also set deadlines on how long you are allowed to take to complete this process.
Rotterdam Municipality website with info on registering https://www.rotterdam.nl/loket/registration/
PDF form to fill out and bring with you to appointment at the municipality (make sure you get this from the official website so it is up to date!) https://www.rotterdam.nl/loket/documentenkcc/vestigingVanuitBuitenland.pdf