Do I need to format my external SD Card? I have a Samsung Galaxy S 5 and will be adding a Class 10, 64 Gig micro SDXC UHS-1 Card. I've seen people refer to formatting an SD card. How do I know if that's necessary in my case?

*Edit: I should have said it's a brand new, unused card.
Not to remain in any doubt, its the best practice to get your card formatted from within your android device.  In setting... storage settings you are going to find the options to do so.