Most of the relays live behind the fuse box so it's probably one of those. Is it literally only when you are driving? How about stationary with engine running, stationary with the ignition on and the engine not running etc.? Are your heater control flaps motor driven?.sometime these stick and the motors/gears make clicking noises. Any thing to do with intermittent wipers?these have a relay which will click once per wipe
New to driving or not, I think you will have to give us some more clues and investigate a bit more yourself.