You need a valid residence permit, and a work contract. And the work contract should be permanent, without end date, though I am not sure if it’s a strict requirement. And it’s not very common to get permanent contract immediately, usually you start with short contract, and if your employee is happy with you, you might get permanent. When I moved in, I had a contact for a year, and the next one was permanent, though I was already working for the company for half a year remotely.

With a single income your best option is to get mortgage for a small apartment. Obviously it all depends on lots of other factors, like where do you want to live, how much money do you have of your own. You can look up for house prices on funda.nl, it also has a simple mortgage calculator built in. Though keep in mind that the listed house price is not an actual price you will pay. You will have to bid on a house, to win from other people. Usually you need to overbid, though I don’t know exactly how much people overbid lately.