A few considerations:
1. The Centennial pool in Longmont should be open on Sunday evenings for roll practice starting in January. Show up with a kayak, paddle, skirt, don't be afraid to ask for help and there should be some folks more than happy to help you learn the basics of a roll and strokes. Go to the pool all you can all winter to work on your skills. I know I benefit from the off season practice, and my kids do as well. Confluence Kayaks in Denver has an indoor pool for roll practice - that would also allow you to demo several newer kayaks.
2. Any kayak is better than no kayak to get you started. That said, the newer the kayak the better the ergonomics (comfort). At some point in the first year or couple years you are likely to upgrade the kayak anyway, or add a second or third kayak to the fleet.
3. I am a big fan of the Jackson Kayak "FUN" series, starting with 2nd generation (2007) through current. It's a good mix of a river runner / playboat. Comfortable, forgiving, easy to roll, etc. Each of my kids and several family members/friends all started out in the FUN series, and continue to paddle them. Similar kayaks are the WaveSport Fuse series and even the EZG series, some of which may be cheaper than a Jackson.