How do I get P3D

I have recently been watching a load of videos on twitch about flight sim X,  it looked really good and graphically, awesome, So I decided to download the steam version.   I have started to use it and it isnt anywhere near as good as the videos,  for example, you cant use the displays in the center panel, you cant load and unload passenger and goods.  So, I asked the question on forum why is my version graphically and usability wise nothing like the videosI have watched,  the answer I got was that they are using P3d verion..  

What is it, how do I get it installed...and how much is it.  I can't find the download on Steam....

Thank you so much