I'm at the beginning of the game and trying to pick the lock for the back room in the office. I've clicked the '?' and read the explanation of how lock picking works. But I can't even get past the first tumbler. I need someone to explain to me how to do lock picking in this game. The explanation in-game and in walkthroughs seems pretty straightforward, but there's obviously something I'm missing.

You cannot pick that lock. First you have to achieve mastery of lock picking. You can get this in the late game if you do the side-quests of Boots. Look for a Detective and do his tasks.