Switching my iPhone from T-Mobile to AT&T. Will I lose all of my photos, text messages, etc?

I requested an unlock from T-Mobile and got an email telling me I can either put in a non-Tmobile sim card or use the T-Mobile sim and backup all of my data and restore. My understanding is now I can take my iPhone in to ATT and they will replace the sim card and I should be good to go. Is this correct? And if it does work smoothly like that, will I lose all of what's stored on my phone? Because it seems like when you put in a new sim card, you have to log back into your iPhone and it acts like you just bought it, so I'm worried

Does my iphone get damaged if i turn it off for a year?

I have an iphone 7plus that i planned on keeping for another year or so to use but my ******* brother used it for a few days. If i charge it fully and turn it off to keep for a year is there any damage caused? I'm p i s s e d

How much is my broken iPhone 8 Plus 64 GB Worth?

The screen and camera got repaired, but the main board is damaged and it won't update or restore and when i restored it I can't get it to work or connect to the server to continue, so the parts gotta be worth something? Oh and how my phone got damaged, my autistic brother threw it hard to the ground when he was angry at me, so…

IPhone app for screen recording?

I have an iPhone and I want to record a video from safari but the screen recorder doesn't record the sound so is there an app that does? I've tried checking a few but they all do the same thing

Why are texts still coming to my iPhone, but not my Android?

I recently switched from an iPhone to an Android, and have several friends with iPhones who no longer seem to be able to send texts to me or receive them from me. My iPhone is still in my possession, but is off most of the time -- I only turn it on every now and again to access contact info and such that I still haven't switched over to the Android. It has no service other than Wi-Fi.

I turned it on today and had 32 text messages -- all replies to texts that I had sent from my Android. Of these texts, there were only five that actually did show up on my Android (all from my husband, who has an iPhone and has never had any issues contacting my Android).

Why are the texts still coming to my iPhone when it has no signal? Is it because of the phone being connected to Wi-Fi even though it stays powered off 99 percent of the time? How can I fix this?

Also, there doesn't seem to be a problem with calling iPhones from my Android, but some of the iPhone users who are unable to send me texts are also unable to call my Android.

How can I fix these issues?