In the past there was one more grammatical number in Polish - dual, which referred to exactly two objects. You can see that in some sayings such as 'Mądrej głowie dość dwie słowie'.
And that is why we say 'dwoje drzwi' or 'dwoje skrzypiec'.
Don't exeggarate! Although some of the expressions are common, in general we don't speak that way!
I have recently heard (and used) expressions taken from English slang. - Fail - Epic failure - Sorry - LOL (in Poland 'lol' is quite ironical, so be aware of using it) - ROTFL - What's up?
And the last thing - it is more and more popular to write 'łał' instead of 'wow'.
Przemyśl - Pshem-i ("y" sound)-shl, but the second "sh" is pronunced "ś". Rzeszów - Shesh-ouf, but the first "sh" is a specific polish sound - "ż". Tarnawce - Tar-nav-tse pronunced with polish "r".
If you knew how to read, you wouldn't have any problems with these names.