Can I proceed my second marriage to the Polish girlfriend?

Sorry but as by Polish law you are not free to marry you will not be able to marry there.You will have to marry in Pakistan but what concerns me is that your 'girlfriend' would be fully aware or should be that Poland does not support polygamous marriages so it makes me wonder if she is aware you already have a wife. Once you are married Poland will legally recognise the marriage and would accept both spouses for residency purposes but even getting married does not guarantee you residency.