Hi
I want to work on a project which includes connecting different sensors to the arduino and display the results on the pc.
which Arduino do you advice me to get the micro or nano ?
Either will work.
Neither are particularly repairable if you damage the processor. Uno with DIP '328P is good choice for starting out for just that reason.
I would go with the micro, it has a tiny bit more ram and some extra USB functionality.
If you use the serial via usb, which they both can do, the only difference seems the RAM.
If the extra 512 bytes is not necessary, just get the cheaper one.
Like CrossRoads, I recommend the Uno if you do not need the size factor.