Christian,
Take a look at this post that I wrote about what pilots earn. Now of course this is about what airline pilots earn. CFIs are paid much less and right now it is impossible to say how long it will take to get to the airlines. Now once you do get to the airlines, particularly the majors, you can really start raking it in.
https://airlinepilot.life/t/what-do-pilots-really-earn/16495/2
Chris