No problem, I'm doing a quick search for "CondaHTTPError: HTTP 000 CONNECTION FAILED for url" this error and I've been finding a few threads you can try. There's some weird conda errors. You have no environments set up titles QIIME2 that's why: "conda env remove -n qiime2-2018.4" doesn't work.
The last thing is maybe some sort of error/virus scanner that may be preventing this. Also Apple has a SPI that prevents some modifications of the installation of scripts you want to run. (About System Integrity Protection on your Mac - Apple Support) However this wasn't an issue when I installed through the conda commands.