Yes, you surely can work even full-time and study part-time. Part-time students usually study twice a month over the weekend (or 2-3 days a week in the evenings). You can choose between a private and public universities; it's usually cheaper to study in a public school, but not always.
It shouldn't be too difficult to find a job in a big city - but you'd better work on your English and Polish to have better chances. Living in Poland is not cheap so unless you have a good job and make at least 3,000-4,000 Zlotych a month, you won't be a very happy student overall (financially-wise).
