My laptop fan is too loud, what can I do about it?

My consumption is not extremely high:

These details are irrelevant.

What is the temperature of your CPU and GPU?

I suspect very high, and then it's important that the fans run at full speed.

Look at the temperature. It could also be that dust has built up in the fans.

So from 50 to 75

The temperature is from 50 to 75.

But then I have to unscrew the laptop, can I do something wrong and damage it, or the guarantee disappears

It would be good if you could find out which fan in the laptop (if you have more than one) is loud. Otherwise, you should also look in the task manager to see what loads the CPU the most (because the fan is usually also attached to it). Then restarting your laptop might help, which will shut down all unnecessary background services. If that doesn't do anything either, you could download software from a third party provider to get the load off the other components of your laptop along with the readings from the sensors on your fans. If your fan is spinning at an extremely high rate there, but your CPU still gets hot, your fan could be broken. If the temperature is very high according to the sensors, even though your laptop is not hot, the sensors in your laptop may be broken.

My laptop gets very warm immediately, even though there are almost no programs running

Then you could have malware on your computer. I would then recommend that you have an antivirus program perform a complete scan of your computer.

You can't really go wrong, there are also many tutorials on the internet, you can have a look. Warranty is almost always void, but if the laptop is still so young that it still has a warranty on it, it is unlikely that the fans will have full anyway.