Formal:
* Jak się Pani/Pan nazywa? (For a woman/man) - This is the most formal way to ask, and is used when addressing someone you don't know well or who is older than you.
* Jak się nazywa? (For anyone, less formal than above) - This is still polite but slightly less formal than the previous option.
Informal:
* Jak masz na imię? - This is the most common and informal way to ask, used for friends, family, and people you know well.
* Jak ci na imię? - Similar to the previous option, this is also informal and commonly used among friends.
Additional notes:
* You can also ask for someone's last name by adding "nazwisko" (last name) to the end of the sentence, for example: "Jak się Pani/Pan nazywa nazwisko?"
* When introducing yourself, you can use the phrase "Nazywam się..." (My name is...).
Remember that the best option for you depends on the context and your relationship with the person you are speaking to.