What are the phases after graduation?
With your frozen ATPL or MPL in hand, you are not yet an airline pilot. Between graduating and your initial flight as a first officer without supervision, you still have to get through an application, a type rating, line training and a consolidation period. And sometimes a wait, if the job market is against you.
You should not buy a type rating speculatively. Only buy a type rating if an airline hires you on condition of that rating, or if you do it with the airline itself. A rating without a job expires eventually. Which type makes sense depends on who wants to hire you. The type rating consists of theory and simulator training on the aircraft type, ending with a skill test in a classroom and full flight simulator. This is followed by base training, which involves take-offs and landings in the real aircraft, without passengers, at an airfield.
Line training, also called line flying under supervision (LIFUS), is the phase in which you fly real line flights with passengers under the supervision of a designated training captain in the airline network. You apply the procedures from the operator conversion course in practice. At the end you must be able to conduct a safe and efficient flight in your role, which is concluded with a line check. This check flight releases you as a first officer. How long it takes is set by the airline in its operations manual, based on your experience, the aircraft type and the type of operation.
Consolidation is the period directly after your line training in which you still count as inexperienced. The airline sets out in its operations manual how it rosters inexperienced crew members. As long as you count as inexperienced, the airline takes this into account in rostering, for example by not pairing you with another inexperienced pilot. After that, you have to stay current.