I am new to speedrunning this game and I would like to know if switching to Classic camera would lose a significant amount of time.

From what I remember, Classic Camera is slower because you have to watch the character attacking forward and returning to place, but with Free-Form if you stand in front of the enemy you can cancel this. But if I'm not mistaken I believe I was told over the course of the run it's only 30 seconds loss?(Someone more knowledgeable can correct me)

Yeah in free camera you save a handful of frames from certain attacks by just being closer and making the movement/spell animations shorter. Overall its not a huge time save, like 1-2 minutes max on the entire run.