Welcome, Calvin!
Since this is all new to you, we have a couple of videos that may help to get you started climbing the learning curve for O gauge command control.
I cover the operation of the Lionel TMCC System in this one, and the MTH DCS System in this one.
Both videos are available on DVD.
There is a lot to learn when you are just starting out, but the learning process itself can be a lot of fun.