It is your responsibility to organise employment, but there is a large amount of resource information available from the Year Abroad Moodle Page.
You can also register with the University Careers Service.
The Year Abroad Office can supply Convention de Stage (French) or Convenio (Spanish) once a work placement is approved. These documents are needed for your visa application.
If your work placement/internship is in France, it should be a paid internship with the minimum rate of EUR 4.03/hour bound by French labour law. Read more on the Service-Public.fr website.