i will be visiting Poland for an exchange semester, i want to know, can i use euro as currency in poland like in normal shops, malls etc or only PLN/polishzloty is only accepted
Outside of tourist-trap areas, it's Zlotys only. The Zloty is actually a fairly substantial currency nowadays and it's rare to see anyone paying in Euro, or advertising that they accept Euros.
BTW - Although Poland is theoretically committed to joining the Euro, there is no timescale for this being done. Joining the Euro would require a 2/3rds majority vote in the Polish parliament (Sejm), and there is no chance of this happening for the forseeable future. Similar to other non-Eurozone countries such as the UK, the Poles have quite sensibly looked at the absolute disaster that the Eurozone has been and counted themselves lucky that they have not been part of it. Polling shows as many as 70% of the population opposes Euro membership.