Yes, you can OC from 18 years up. You do need to make sure that the sidearm is not concealed while wearing clothing or driving.
You should also stay away from school zones (1000 feet).
Your sidearm must be "Utah unloaded", meaning a full mag and empty chamber or in a revolver, empty chamber under hammer and empty chamber in next cylinder. Basically you need to perform two (2) actions to fire. Rack and trigger or trigger twice.
If I left anything out, I am sure someone will chime in.
Enjoy your stay!