To right-click, you can do a two-finger tap -- you might have to enable this in System Preferences > Trackpad > Point and Click > Secondary Click.

Also, for some of these questions, it would be helpful to know what operating system you're running. Mission Control is new to Lion (10.7) and has all the fancy four-finger swipes to reveal the desktop, etc. If you're using something earlier -- and actually, I still prefer my hot corners to the weird four-finger flick -- you can set hot corners to reveal the desktop, sleep the display, etc.

I am a big fan of MacWorld if I can't figure out how to do something: http://www.macworld.com/howto.html

Hope it becomes less frustrating soon!