I learned to ski in CO and skied Eldora, Loveland and Arapahoe Basin as a beginner. The only one of the three I would not recommend for a first-timer is A-Basin. The bunny hill there is very small and none of the longer green runs are suitable for first-timers, IMO. Eldora and Loveland both have longer greens that are manageable by first-timers, in addition to the bunny hills.