Original El Capitan 10.11.0? I'm looking to upgrade my Yosemite system with El Capitan but I can only find 10.11.1 versions. Need the original. Any help? Any thoughts?
Assuming you "purchased" El Capitan during it's availability you can download it from the App Store in the usual way. You will actually get 10.11.6 - there are no reasons to install 10.11.0, and Apple does not have an all-versions archive.

If you did not get El Capitan while it was available then you can't get it. Sierra is the current offering, but wait a few weeks for 10.12.1.