Law / How does the Polish Government work? [3]

I'm from Jasło. I grew up in Poland but most of mg education has been in America so I never learned about the government of Poland.

If you know the way the American government operates, can you compare it to Poland's?

How are people elected?
What are the courts? (Such as supreme court of usa)
Who makes final decisions? (Congress in the usa)
Is the Sejm the same as Congress in the usa?