There are dorms in Warsaw. Each belongs to an University, so if you're not a student of Politechnika Warszawska or Uniwersytet Warszawski (or other big public Warsaw's uni), then you will not get a place in them. You should ask your school weather they provide something. There is bigger demand than supply for dormitories in Warsaw, because they're cheaper than renting a room on free market. Who will get dormitory is calculated according to algorithm taking into account family earning, distance to home etc.
Prices in UW dorms:
o Dom Studenta nr 1 "Muchomorek"- 290, 360 lub 450 zł,
o Dom Studenta nr 2 "Żwirek" - 290, 360 lub 450 zł,
o Dom Studenta nr 3 "KIC" - 280, 340 lub 380 zł,
o Dom Studenta nr 4 "Zamenhof" - 460 lub 560 zł,
o Dom Studenta nr 5 "Smyczkowa" - 340 lub 390 zł,
o Dom Studenta nr 6 "Radomska"- 430 lub 445 zł.
Images of UW dorms (click Galeria)
Dorms differs a lot according to standard. There are some new apartments with shared kitchen between 2 rooms and there are old block flats with small 14m2 rooms and 3 students in it and 1 kitchen and 1 bathroom per 13 rooms (13*3 = 39 people) floor. There is always option to pay more and share room with only 1 person or live alone.
What not to do... Don't say that you don't like vodka. What to do... When you for the party bring beers or vodka.
General experience is only positive.
I've seen your other topic where you write that you Alma Mater is Vistula. And I don't see anything about dorms on their website. Ask them about accommodation and read perhaps this:
I am not from Warsaw, but fast googling gave me result about private dorm:
The price depends on the number of people in the room and its size and ranges from 590 PLN to 750 PLN per 1 person (no extra charge!). The rooms are for 2-4 persons