Basically, the police will want to have a reason to register you - having a job is a good excuse. Basically you can spend 3 months looking for work without paperwork. The police want to see your contract and the magistrate wants to see the paper that says your residence is registered. Goverment assistance as in dole is for residents -who have worked here before unemployment - there is a thing called integration allowance, but if you'd qualify that'd be another question.
So you are all free to enter and seek work. Once you get a job then getting the residence declared is a stint to the different offices.