moving next year

HI! I am planning a move to Colorado next summer/fall. I am a 23-year-old female and will be moving by myself. I am curious on peoples' opinions of some areas to scope out when I visit in a few months. Some things I am looking for: lively, opportunities to meet people similar in age, access to outdoors for hiking/running, fun bars and restaurants, monthly rent around 1500 (open to roommates if I can find in time), would love a walkable downtown of some sort (i will have a car with me as well). I am definitely going to check out Denver because that is an option I am considering but wanted to know other places people recommend. Ive heard about Boulder and Fort Collins but hear they are more expensive and it can be more difficult to establish friendships. Any adivce is appreciated!