Why did I get an activation lock in regards to 'Find my iPhone'?

So yesterday I was in the middle of texting my friend until my phone switched off then like 5 seconds later the apple logo came up. Then I was told to enter my Apple ID and password etc and something to with find my iPhone. I can't remember the exact words but it also said "it may take a few minutes to activate your phone". I bought my iPhone from a second hand shop in 2014. So what did this mean?

I found an broken iPhone 7. How do I find out the gigabytes and service provider?

I found an iPhone 7 at a local festival. The phone is shattered and the screen no longer turns on. The sim card was broken in the phone but I still have yet to attempt to connect it to itunes. I plan on selling it but I need to figure out the gigabytes and the service provider of the phone. Because the screen doesn't work, I have had trouble doing so. Please help! I found an broken iPhone 7. How do I find out the gigabytes and service provider - 1

Little sister broke my phone - am I overreacting?

I'm 14 and have an iPhone 6, my little sister dropped my phone onto the kitchen floor and smashed it, my mum said she'll get it fixed for me this week but I told my sister to leave me alone and went up to my room and cried hysterically. I don't even know why I'm sad considering it isn't that bad and I'm getting it fixed this week but is this an overreaction?

If hair not falling out and no receding then hair is still growing, right?

I'm a 26 yo male, always had super fast growing and thick hair, hair cut a month, prob more frequent actually. Recently been sick w/mono and random ear infection but over those though been worn down a little still. I got a bad way short hair cut ( I like sort of spiky in front, military ish hair do) and tried to 'alter' it on my own, and it got see through short. I'm impatient about it growing back, and I know hair maybe at best grows .6 inches/mo but the big? I have is as long as my hair isn't falling out in any way, and no receding (though my cowlick which always is big is now very visible under bright light like iPhone photo I snapped), then my hair is fine and just needs like few weeks to get normal-ish, right? I did this one time before as I get obsessive and think I can 'fix' my own hair and it got see-through short but 10 days or so was somewhat respectable. Just wondering. Also lost few pounds in last week or so trying fasting intermittent. That can't do much right as long as no major weight loss? Thanks

Added (1). hairline is not receding or anything just to make clear. I have always had thick hair and frequent hair cuts. It would be like a sudden 180 to have receding. I just got it super short. Though w/the mono my concern was it was affecting thyroid or something and stress, too, as my energy has plunged a lot lately. Gut tells me I'm fine. Just helps mentally if I know that as long as hair isn't falling out at all then I'm not suddenly in big trouble/balding early signs!