Here are some examples of how to use it:
* Proszę o kawę. (Please, I'd like some coffee.)
* Proszę, wejdź. (Please, come in.)
* Proszę o pomoc. (Please, I need help.)
* Proszę, możesz mi to podać? (Please, can you pass me that?)
It's a versatile word and can be used in many situations.