Just to make sure you've done everything correctly; confirm with these two useful guides. vdubt25 is down now so you might have problem enabling the addon for the moment.
https://superrepo.org/get-started/ << updated version 0.1.0 is here
https://seo-michael.co.uk/how-to-install-phoenix-for-xbmc/
Futher - if you get choppy video (like me) and it's not caused by buffering, then you can try turning off video hardware acceleration. Go to "System - Settings - Video". Change "Settings level" at the bottom to "Advanced" - this will reveal a few new menu entries on the left, including "Acceleration". Go to that, turn off video acceleration if it's enabled.
Personally, I find that Kodi's interface leaves a bit to be desired. Too much fussing about clicking here and there. Maybe there's a better interface add-on somewhere, but I use it just now and then so it's tolerable.