1. City to select. I will recommend Cracow, Warsaw or Wroclaw. Sometimes you can find remote job in such a cities, but salary usually higher comparing to other cities in Poland. So you can live, for example, in Katowice, and work for a company in Cracow.
2. CV. Your CV should be short, include only basic information. Main point here to show, how you improved the process or maybe you was promoted. Nobody cares about tools you was using or daily tasks you was doing. Common mistake is to create few pages CV and describe all the daily tasks there. Companies will hate it a lot.
3. Which website to use? The best one is LinkedIn or to apply directly on company website. Using Olx, Pracuj.pl or Gumtree you can find only basic job, like construction worker or work in the shop. If you speak English, it’s enough to apply to a corporation, as a lot of them have entry level positions and experience no needed there. Don’t worry, if you don’t have B2 or C1 language level, try to apply anyway, even if your English is B1, and knowledge of any other languages can help here.
4. Please, read job description in details. Check feedback about company in internet or ask your friends. Ask about atmosphere there, this is very important.
5. Salary expectations. Always ask more, than you expect. One day I applied some job and accepted offer, but later realized, that people from the same band (level) getting few thousands PLN more. Remember, what you will agree at the beginning, usually will be for a long time, so better to ask 2000-3000 PLN more, especially in situation when recruiter contacted you on Linkedin before you applied job.