People born in Poland are eligible to participate in the American Green card lottery program, even if they are living in another country that is not eligible to participate in the draw.
If you are living in Poland you can request for the interview in the local US Embassy and the interview will be held according to your case number.
If you are Polish person living in the USA and selected as a winner in the name selection, then wait for your case number to be current. Whenever the case number of yours becomes current, then contact the USCIS office to change your current US status to LPR status.
Winning the draw will not give you the American entry permit right away but will allow you to apply for it and you must meet all the eligibility requirements of their Immigration program.