How long will it take to reset an iphone and create a new iCloud account?

I need my phone for internet to stay in touch with everyone until I set up this phone and add it to my plan. Just curious how long this will take. It will determine if I will actually get it turned on today or if I'll be re installing all my apps and saving my photos back on this phone. Please help As soon as possible if you have any info or comments.

If two iPhones are synced what all do you see from the other phone?

I have one my best friend gave me because she just got a newer iphone. They are currently synced and I'm in the process of saving the photos to a computer before setting up a new iCloud account. I'm curious what can my friend see besides pictures I take? I'm new to iPhones and I don't want to overload her gallery with pictures I've taken already. Any information you can give please share, thanks so much.

If I create a new iCloud account will it erase my pictures and apps?

My friend sold me her old iphone and it's synced to her new one. If I create a new iCloud will it delete all photos, apps, music, etc? Fine, if that's the case for my phone but my other question is if the same will happen to her phone? She would be so upset if her stuff was erased but I need my own account to activate this phone. Plus, it's getting annoying seeing each others pictures pop up randomly. Any information helps, thank you!

How to log out of iCloud without the password?

An old friend of mine gave me their old iPhone [it's an 8.3] but didn't log out of their iCloud. It's an old email address they haven't used in years and they've tried every old password they can think of and they're not with Apple anymore. What to do?

Can I still get my iPhone 6 screen fixed at Apple?

I dropped it awhile ago and it was pretty bad. Small bits of the glass were missing but it was still working fine.

After a few days of using it, the screen all of a sudden got all f***ed up (I left it in my backpack and when I pulled it out it was like this) and now the screen won't work at all.

When I press the side button, the screen that says "Slide to unlock" still shows but it's very discolored with weird purple vertical lines. On the side I dropped it on, there's even more lines with even more colors and there's patches of black.
TL;DR: phone is completely unusable.

So with all this, am I still able to get this fixed at the Apple Store for $109? I was going to at first because only the glass was cracked, but now I'm not sure if this is fixable.