What is the difference between 'na' and 'w'? And is it the same as in Russian?
Em, quite a broad topic. I don't speak Russian so I won't refer to it, maybe it is similar. Generally speaking na is used in the sense of English on. Na budynku means on top of the building. Na is also used when you want to communicate that you are in place that is associated with some surface rather than building, like parking, airport (airfield), meadow, field, courtyard etc. The last usage of na is with activities. One can be na mszy - at a mass but w kościele - in a church, na lekcji - on a lesson but w szkole - in a school (building).
W is associated with buildings, and something that is around you:
- w szkole - in a school
- w lesie - in a forest
- w górach - in the mountains
- na górze - on the mountain