I'm a member of ARRL mostly so I can help support the hobby and read about stuff in the QST magazine that I barely understand.
It is helpful, all joking aside. especially to get familiar with terminology, contesting, QRP, and to wet your appetite to get your General.
Check out www.w0cra.org
(Colorado Repeater Association). they have a Csprgs repeater that I beleive is linked to the Denver repeaters. if you dial that into your radio, there's a good chance you'll hear more traffic. it's also good to practice setting freqs/memories/tones, etc.
Also...program in the Colorado Connection repeaters...also linked, but close to statewide. Again...more chance for traffic there.
Both of those repeaters have check-ins on a regular basis. I participated in those for a while - it's cool to listen, check in, get the lingo down, etc.
I started to google 'colorado repeaters' and came up with a ton of clubs and repeaters for both 2m/440, programed them into the radio. (rocky mtn. radio league, CRA, etc) I'm guilty of scanning repeaters to to listen to what's out there on my way home. I'll typically hear someone, somewhere.