I mainly use my laptop for surfing the Internet and for school.
I mainly play on the console, but now and then I also like to play more complex games on the laptop and it gets pretty hot.
Is it really bad and will the CPU and / or graphics card be damaged and how much?
No, the parts are designed for that. Such a CPU / GPU can easily last 10 years and if they get constantly hot maybe 9 (minimum, mind you). So it doesn't really matter.
It reduces the lifespan of the components if they get hot often and for a long time, but how much depends on the specific components, albeit marginally.
Nothing is damaged at first, the parts slow down and if all else fails, the laptop simply switches off to protect the parts.
It's best to clean it regularly and then I don't see a big problem.
Temperatures that are too high are not good for hardware. The rake inputs throttle themselves when they get too hot. As long as they generate the heat themselves and the heat does not come from standing in the sun or from other components of the computer, it will not break directly.
Even if the components do not break immediately due to the high temperatures, their expected service life is noticeably shortened as a result - on the other hand, a computer is often not used as long as it can, but is no longer used when it is out of date or (esp. With laptops) if they break mechanically (hinges, falling off…)
In itself, a high load should not be a problem, because these things are (in this respect) actually quite robust. If the parts in question are already causing problems, a heavy load can theoretically give them the last remainder, but in this case a failure could be expected soon anyway.
