My question is will that affect my application? I don't know what the law says about criminal records in Poland
You need to disclose it, nothing more. It shouldn't disqualify you as long as everything else is in order, as long as you're not detained at any point during the proceedings. If you get sentenced to prison, then the application will be terminated. However, you can reapply again after being released, as long as you don't get deported.