do you have any tip/advice regarding Poland
In terms of living - stick to bigger cities, for a young guy there is more to do there and people are more open minded.
Warsaw, Krakow, Tri-city, Wroclaw - these are nice, Poznan should also be OK.
In Warsaw you will earn more, but will also pay more for accommodation and going out.
Try to find someone to share apartment with, it will be cheaper than living alone, but don't rent a room only, they are usually untidy as people who have been put together randomly find it difficult to share responsibilities of keeping place clean.
Try to find a place outside with good communication links to the center (but outside center).
Compare prices of furnished vs. unfurnished, you can buy stuff you need second hand (allegro.pl is a Polish equivalent to e-bay, but ebay also functions in Poland).
In terms of salary - don't expect too much, you are still young and Poland does not pay much for entry positions. What they were offering to you is perfectly fine, if you want to move (for sake of experience, take it) - if you want to move for money, you may need to finish studies first and get more experience. You will earn substantially more one or two levels up.
That's all from the top of my head - any specific areas that you are interested in?