May I suggest that Picard is simply not the best tool for the task of just renaming/sorting music files. It’s great for tagging (initial, correcting, completing), but if you don’t need that, other tools may be a better fit.
I’ve used mp3rename (commandline) and amarok (GUI) in the past. On Linux, though. Windows users may give better suggestions.
That said, you can accomplish your task (and then some!) with Picard. But it may sometimes feel like driving in a screw with a hammer.