Can't download El Capitan from Appstore. Constant Spinning Wheel Okay so here is the story..

I had just bought this Mac... I tried installing some software, and nothing was installing... kept getting this stupid error.


  The Installer encountered an error that caused the installation to fail. 
  Contact the software manufacturer for assistance.


 

So I thought it was like that for one particular program, so I began looking on the internet. Eventually I just forgot about it, until I tried to install another piece of software. Again the same issue... I soon realized after that it was happening to every single piece of software that I was trying to install that involved an installer package...

So then I tried to download and install El Capitan from scratch... But now I have run into another issue... app store won't download it... I'm stuck with this spinning wheel at the top left corner where the "Back" and "Forward" buttons are with the "Download" button grayed out after clicking on it. No response or any indication that it is downloading.

 

Any ideas? Support is out for the day, so I hope I can get an answer by tonight.
This is not really a true answer. But eventually after attempting to download El Capitan several times, it all of a sudden began to download. Once it downloaded I put the OS on a flash drive, booted off of it, wiped the drive, and performed a clean install. After that the system has been operating flawlessly. I guess when they gave it to me, something must have gone wrong during the install that got overlooked? not sure. 

To be honest I do not know what software I was trying to install first when this all began. But it was something simple. This happened to me on every installation of any product that involved using an installation package. i.e. Adobe flash, Teamviewer, my logitech mouse drivers. It was happening on everything I tried to install. I just don't remember the first thing it was I tried to install.

Anyways now it's all up and running after the clean install, and performs flawlessly. Hopefully this doesn't occur to me again. 

Thanks,
Sicariuxs