The most sought after skills vary depending on the area of software development eg if you want to work in banking/finance you'll ideally need to know C++ and MFC. If you want to be a software developer what you really need is to know two computer languages very, very well, rather than a bit of this and a bit of that. You'll pick up the other stuff as you go along. Concentrate on honing either your Java or C++ (ideally C++ as it's more complex than Java and hence there is a shortage of C++ programmers compared to Java) and then try to get a position as a junior programmer in that language.
I learned that most IT jobs in Poland don't require you to speak Polish.
If you have a skill set they need, the Polish language won't matter so much but if you're looking for a junior programming position I'm not so sure. Although there are plenty of foreign nationals working in Polish offices, most of them have been hired because they are experienced. Most communication in Polish teams takes place po Polsku. So continue to work hard at your Polish too :))