Welcome to the forum
. There are plenty of trails that you can run right outside of Denver. problem for now is that most are still closed. But that being said they should start to open any day now
. The higher elevation ones start opening in June.
I would suggest getting yourself a Trail book. the ones from Funtrex seem to be the most accurate. The other thing is to keep an eye on this site as someone usually has something going about every weekend.
Good time and Great people.
Happy Trails, Chad