I'm looking for a laptop with a relatively good performance but only have 250 euro. Which processor and which brand would be good. Used laptops also work. But I don't want a Chromebook
Will be difficult with this budget. Instead, look for tablets or, if you want it to be Windows, for computer sticks. These are actually relatively cheap and only have to be plugged into a screen via HDMI. You will need this extra, as well as a keyboard and mouse.
Yes, I think that would also make more sense
No, 250 euro for a "good" laptop is not enough. You may be able to search for a 13 inch Macbook from 2013-2014. These cost around 350 euro and are still performing well after so many years.