P90X? Or P90 Master Series?

As usual I probably bit off more than I can chew.
I have a habit of jumping into things without being fully prepares.
I recently purchased P90X off of Ebay. it is an extreme work out series of 13 dvd's. I then found out I needed a chin up, pull up bar, so I bought a nice one of those too...
I have a friend who has completed P90x so I called her to get dome advice... she told me that I probably should start with P90 Master series. A couple of reasons is because I am 50 years old, and haven't been active in sports for about 4-5 years. Also,. I will want to know the "Moves" before attempting P90X!
She lent me two dvd's from the P90 Master Series. Today i attempted the "sculpting" dvd. It was very tough, but not impossible. I completed the workout. It was about 45 minutes with stretching on both ends of the work out.
I found myself not knowing much of how the moves were done, so my friend was correct.
Also am trying to figure out how much weight to use for the exercises for the first time is a challenge as well. I think it will improve over time!
Now I am thinking I would like the whole P90 masters series to work out with for a month before doing the P90X.
Yesterday I asked Eric if he was always sore from working out? His reply, "Pretty much!" lol
Great, that's something to look forward to forever...