Quitting smoking would be one of my wishes that I'm definately going to try
That will save you about 400 PLN.
A two bedroom apartment is not a necessity, one bedroom will do just fine.
That will save you from 200 to 500 PLN.
at least over here (Netherlands) a steak or a nice piece of fish is not that expensive, around 2 euro in the supermarket for 140 grams.
Poland is not a beef and good fish country. They eat mainly pork and chicken. For most Poles, fish means herring, smoked mackarel, and frozen filets, mostly of pollock and Vietnamese catfish (panga). Salmon and trout are upscale. What you as a Dutchman would consider "nice fish" is largely unavailable here, or very expensive when it is available. Even more so for seafood. Trying to maintain a beef and good fish diet in Poland is going to cost you.
I need internet in the apartment, but no landline phone.
The cost for internet is about 75 PLN, with or without the landline phone.
And I'm not a big drinker.
I will go out in the weekend and will drink about 6 beers a night.
Trying to figure out how those two quotes don't contradict each other. In my opinion, someone who drinks 12 to 18 beers on the weekend is definitely a heavy drinker, and probably has a drinking problem.
i think nightlife is a good way to get to know people.
Probably one of the worst ways of meeting quality people who can help you adjust and help you advance socially and professionally, who are going to avoid you if you are three sheets to the wind. One of the best ways to meet drunk losers who will drag you down. You really have to think this one out.
Please also answer my question about ZUS.
The ZUS is taken out of the 6500. The net pay is what's left after ZUS, taxes and insurance are taken out.
Sorry, but I'm still detecting a distinct odor of immaturity here in your part. If you consider your stay in Poland an opportunity to become responsible, disciplined and mature, go for it. If you don't want to leave your cocoon of comfort, try to find a job at home.
Another thing. Poland is not a bicycle country, either, and bicycle theft is a MAJOR problem. Actually, it's the national sport. If you come here with a nice bike, it will be stolen within days.