Do I have to stop pedaling when shifting up the front chainring?
Use the Clutch!

This is what I always tell people when I'm teaching them how to shift gears properly. Chain-rings and Cogs are machined with *pickup points" that assist transferring the chain from one ring to the other, they only work while you're turning the cranks. So I tell people to let all the power off of their pedals, but keep the cranks turning and don't step back into the pedals with any force until the chain has fully shifted.