Potential compatabilty issues? help

Hi sorry if i have posted this in the wrong area but im new to this site.

Im thinking of buying a new mac mini that i will use for my studies when i go to sixth form in september, but im worried that there might be some compatability issues with windows based files, such as if i need to email someone something but they are one a windows pc, or if i need to open a file that was designed on a windows pc. Does anyone know of any that i should know about? This would be my first mac so i dont know the deal with them. Should i just stick with a windows pc?

Any info would be much appreciated. thanks alot.