Is this your first smartphone?!?!
You will find many on here who use nothing on the screen, others who always use a protector.
Personally, I never go without - it's cheap insurance, and helps with resale.
I love tempered glass protectors, but avoided them for the S7 due to the minor curve at the screen edge - most seem unsatisfied with the resulting appearance.
I actually just installed a Yootech film protector tonight on a new S7 (I run the shower a few minutes so the steam knocks the dust from the air). It goes edge to edge, and will be fine with the Spagen Neo Hybrid case it will reside in.