How do you carrier unlock a iPhone 7 for free?

My grandmother recently passed on, and my mother said she I could have her iPhone. When I put the sim card from my Verizon iPhone 6s into her AT&T iPhone 7 it said the sim card could not be activated. When I called AT&T, they said they couldn't because she didn't pay her phone bill (She was in the hospital for about 8 months and left her phone in her house). So, is there anyway I can do it myself for free?

IPhone not sorting music properly?

So I'm using iPhone SE with the latest iOS. I just added some new songs to the list and all of a sudden, my music list is out of shape. I have my songs arranged by artist, which is then arranged in alphabetical order, but now, the new songs are arranged fine, but everything else is arranged under a question mark. I checked and double checked iTunes, the only problem I can see is that it constantly updates all songs when I add one. Could this be related? Any solutions to this problem?

How can I break my habit of constantly restarting my phone for no reason? - 2

So I recently had to get a new iPhone because I broke my last iphone. I broke my last phone because I kept on constantly restarting it for no reason for the past year and it messed up the phone and broke it. I had to get a new phone a few days ago and I ended up having to upgrade to the iphone 8 since they were out of the 7. I want to find a way to break my habit of constantly restarting phones so that I don't break this one. How can I break this habit?

Is the iphone SE any good? - 1

I have an lg 3 escape but I want to make the switch to an iphone. Sadly, the only iphone my provider has available anymore is an SE. I'm worried it's too old or small or there's something wrong with it that I'm not aware of because I've never had an iphone.

Does my iPhone have a one year warranty?

I bought an iPhone 7 11 months ago and yesterday it would shut off when I tried to turn it on. I haven't dropped it or anything like that and I have heard that apple has a one year warranty on there products.so will they replace my phone?

Added (1). thanks I took it to the apple store and after trying to fix it they just gave me a new phone