Hey Op,
We've all started somewhere. It's good to see you beginning. That is the important thing. I am not in Colorado, so I comment on the trails. BUT, I do have an idea.
#1) I bought a number of local trail books. I would suggest "Backcountry Adventures - Colorado" by Massey, Wilson & Titus. I have a number of these books for different states. They are great. There are maps, local history, GPS waypoints and trail ratings with descriptions. Try the easy stuff first.
#2) On Youtube, many people have posted their entire trail drive for different trails. You could watch a trail on youtube and get an idea of its difficulty. I do this when I am going to try a trail I've never been on.
Have Fun