you don't technically have to study for a loft since there's no oral and it's not pass/ fail. But you should always be ready for a PC since it could change to that due to Capt needing one, or other scheduling snafus. Good CRM and communication works well in trouble-shooting. I recommend the FO fly while the Capt runs QRH and communicates/ manages. Don't dig a deeper hole for yourself by making the initial problem worse.

You'll usually end up having fun and learning some stuff