Hi again,Louanna!
For now I have just few phrases for you, but without pronunciation, I suggest you using Speech Synthesizer (link in Seana's post)- it's very very good and after careful writing down words and listening, you can make notes with your own pronunciation, which will probably be much better than my poor attempts!

Here are some useful expressions (be careful with spelling!):
FORMAL
* Good morning -
Dzień dobry
* Goodbye -
Do widzenia
* Good night -
Dobranoc
* Thank you very much -
Dziękuję bardzo
* Bon apetite -
Smacznego
* I'm sorry, I don't speak Polish -
Przepraszam, nie mówię po polsku
* Excuse me, do you speak English? -
Przepraszam, czy mówi Pan / Pani po angielsku? / (Pan- to a man; Pani- to a woman)
* I'm sorry, I don't understand -
Przepraszam, nie rozumiem
* Excuse me, where is the toilet / nearest post office / police station / supermarket / church / (...) Street? -
Przepraszam, gdzie jest toaleta / najbliższa poczta / posterunek policji / supermarket / kościół / ulica (...)?
* I'd like...(in a restaurant) -
Poproszę...
* I'm very grateful, thank you -
Jestem bardzo wdzięczna, dziękuję
* The flight was calm, I feel fine -
Lot był spokojny, czuję się dobrze
INFORMAL
* Hello, bye -
Cześć
* Thanks -
Dzięki
* What kinds of music do you like? -
Jaką lubisz muzykę?
* What bands do you like? -
Jakie zespoły lubisz?
* It's okey -
Jest okey
It's just basic examples, but maybe here
http://www.learn-polish-language-software.com/phrases/FSPolish.htm you'll also find few more things.
I'll try to find somethig more on the web and give you few more expressions as quickly as possible. And be careful with Korena's link- there are few spelling mistakes
Greetings!