Could you suggest a good laptop that I can downgrade from Win 10 to Win7. It should have a number pad on the right side of the button (I know that support has stopped)
What do you want to spend? You can also buy one without Win 10, because you can install Win 7 directly.
Look for used laptops before 2013 (Windows 8 appeared there). The problem with new computers is that there are no drivers for Windows 7 anymore.
Around 500 euro could you show me a "new device"?
Sorry, sorry to disappoint you. Apparently Windows 7 is only supported by Intel Cpus up to the 6th generation, so it will probably have to be a used laptop or you will resign yourself to Win10.
Are there any more from 2017 or 18?
Bad chances, the chip is from 2015, you will find nothing new there. Since you will probably have to buy something used.
New computer old operating system is not possible as already mentioned because of the missing drivers.
In principle you can install Windows 7 on all computers, but on newer ones you often have problems with the drivers. If so, you would have to use an old laptop, but I would not recommend using Windows 7 today