Hey, Thrust, it’s still a little muddy most places, but I have to second the advice to get an app on your phone. Trailforks, like MTBProject, is free and works via the GPS feature of a smartphone, not dependent on cel reception. If you have the app (or even use the Trailforks or MTBProject web sites ahead of time), you can easily inventory easy trails near to and farther from you.
Specifically, Green Mountain has some great views and not too far a drive. North Table Mountain could be another. Many other areas exist which have easy trails but perhaps not known for easy trails.
I’m over in Golden, so don’t know shops in your corner, but Golden Bike Shop and Wheat Ridge Cyclery have been great.
And…get over that old-person jive. Tons of us riding hard are long in the tooth. Just enjoy yourself and don’t worry what anyone thinks of your age or ability.