As the title says I am an first time Mac owner, I brought the 21.5 inch model last night from the Apple store and will have delivered to my house on Monday. I have just a few simple questions below, thanks in advance!! 1. Do I need to purchase any kind of antivirus software for my Mac like norton 360? Or does Mac have it's own antivirus software thats already installed on it? 2. Is there an Mac program that is similiar to microsoft word, powerpoint, etc or do I have to buy the microsoft office for Mac software?