What is it that you are hoping to achieve?
I only want to work with planes like Cessna, KingAir, Piper (only TurboProp), and maybe, maybe, maybe latter with jets like Embraer, LearJet.
This doesn't really mean very much since you have listed a mixture of manufacturers and aircraft types. In a fiercely competitive marketplace it is difficult to understand why you would "only want to work" on this slightly eclectic collection of aircraft and generic manufacturers.
There are opportunities in general aviation in many parts of the world, some more than others. Flight instruction, air taxi, "bush" flying tourists and company support. Many of these opportunities are fiercely fought over by people who themselves often use these routes as "stepping stones" on to further career advancement.
At least two of the manufacture/types you mention are mainly found in business jet operations which itself is a fiercely competitive career path, or third tier (regional) airline operations.
There are many forums here that have a wide variety of contribution and discussion on the many career paths that
might dovetail from the acquisition of a professional qualification. You would be well advised to research much deeper, and have a clearer understanding of what it is that you are asking, in order to get anything other than a vague reply.
One thing you should be aware of though, is that it is an extremely crowded marketplace. That is particularly so at "entry level" and there are no easy pathways.