How to Free Up Space on iPhone 6 16GB

Question

Hello I have an 6+ 16gb memory. I need to make room for iOS 10. 
I have never used iCloud and I'm frustrated with it. So several questions:

1. iCloud says it is still uploading 200+ photos (from when I started yesterday afternoon at just over 800 photos). It says it's used 1.1gb and my phone tells me I have 2.3gb of photos. Does this seem normal?
2. In reading how iCloud works, I think it says that the photos are stored there AND on my phone. Why is this so and what use is using iCloud to store if they are still on my phone?
3. If I open the iCloud icon on my phone, nothing shows in the file. I understand that all photos are not yet uploaded, but does this mean that until the upload is complete I will not be able to see anything at all?

Answer 1

Some of the photos files can be larger if they were Live Photos or HDR Photos, and some can be videos, which might explain why it seems off for have many photos have uploaded.

They are stored in both places until you delete them from your device. iCloud is used as a backup for your photos in case you were to accidentally lose your phone or have to restore the device. After your photos are uploaded to iCloud. Apple says that if you want to delete photos, you need to back them up to a computer before deleting. From what I understand the photos have to have a physical file one ONE of your devices in iCloud. You can set iCloud up in the Mac or PC to download the photos for you so you can delete them from your phone.