Just about everybody takes the ATPL exams rather than the CPL exams. After that you do the hours building, CPL flight training, the IR training, a muti crew course then go job hunting.
This gives you the theoretical minimum to apply for a first officer job in an airline although some companies require you to have a type rating as well before applying.
With a CPL/IR you can take single pilot jobs but you will need 700 hours to do so.