1 I'm the perfect candidate, because I am a hard worker (and a quick learner). / I am the right person for this job, because I am a hard worker (and a quick learner).
2 I would like to apply for the job of waitress.
3 I'm interested in the job of (car) mechanic. / I would like to apply for the job of (car) mechanic.
4 I saw the advertisement / vacancy online.