There is a glut of housing and of office space in Changchun. The city is rapidly expanding and rebuilding. Your employer will assist you to find suitable accommodation, but if you do decide to find something yourself choose carefully.
You should also register as a resident with the local police, which may involve paperwork at other offices and require a fee. It is best to let your employer arrange accommodation for you. Your employer is legally responsible for you.
Apartment blocks have a superintendent who will collect gas and electricity fees once a month. There will be a rubbish collection point near you.