Mac installation problem & folder structure

Just got my new 27 inch iMac and was excited about installing football manager on it. Steam seems to have downloaded ok but when I click on play, football manager won't open. Get an error about send error report to apple etc. anyone have any ideas what could be happening. I'll get more details on the error if needed Tmr but for now any ideas?? Brand new iMac. Also when I initially installed it it asked me that I had to enable some feature On the Mac which I did and I also created a football manager shortcut on my desktop. I'm new to macs.

Also where is the folders located like for graphics etc like on windows. I can't seem to find anything

Thanks

Tom