Sweet, thanks for the details @uria!
Looks like you are running an old version of conda (4.3.24) --- the current version is 4.5.5, and, the config files that ship by default are quite different between the two versions. You are missing the main channels that ship by default now. The first section of the install guide mentions that you need to be running the latest version of conda in order to install these QIIME 2 environment files -- check out the commands listed there to get set up!
Hope that helps! :qiime2: 