Start by dragging your mouse down to system preferences on the dock and open it. If system preferences is not on your dock you can get to it alternatively by opening finder and selecting applications. Scroll through this until you find system preferences which should be located near the bottom because it's usually organized alphabetically. Then select the keyboard and mouse icon. After that click on the trackpad tab and check the option in this screen that says "place two fingers on trackpad and click button to right-click." You will now be able to right click by placing two fingers on the trackpad and clicking the mouse button. Enjoy!