Im like zaxaca. Just keep it simple for now. I have been fly fishing for just over a year now and finally caught my first rainbow trout back in April. Largely in part due to finally taking the sport seriously and trying to get better (unlike last year). Welcome to such a great sport where enjoying nature is just as cool as the fishing itself. Research what flies to use in Colorado along the river your gonna fish and when you get there, pay attention to whats flying around and crawling and try to imitate that to the flies that you have. Work on your casting techniques before hand as well.

Finally, please don't get overwhelmed with fly fishing. There is SO MUCH information out there on how to fly fish that it can get extremely discouraging, but just try and keep things simple and knock one tree down at a time. I have been avid bait fisherman all my life, but now fly fishing has totally taken control of me that I don't even bait fish that much anymore. Good luck