Something else you will have to do is to register in the padrón municipal, the registry of all the people who live in a municipality.
This registration is called Empadronamiento (“padró” in Catalan) and it will be useful to apply for the residence permit, to have a primary care medical center (Cap) assigned, to enroll the children at school and for many other procedures like the use of municipal services such as swimming pools or libraries.
Requesting an appointment to register is faster to get than the NIE. It has to be done through the City Council website or by phone. The wait can be long at times, but with a little patience everything is achieved.