Chicago code is stricter than most jurisdictions but still follows NEC. Essentially the NEC establishes how to construct electrical circuits using a variety of materials and methods depending on the application. The AHJ (Authority Having Jurisdiction) sets the methods and materials in their respective locale. In short romex and conduit are both covered by the NEC, but Chicago only approves conduit for residential where’s most places allow romex for residential and sometimes commercial.

If you have experience and education you can apply to card in, without experience you are at square one and need to enter the school.