How to fix S8 not getting texts anymore?

I've recently got the S8 two weeks ago in a trade in deal from Best Buy with Verizon. I traded it in for an iPhone. When I first tried to text my friend with an iPhone, the messages would still go to the iPhone and not the S8. I fixed the problem by disconnecting my iMessage. However as of last night when texting my friend, it immediately stopped working. I can send messages and they can receive them but they sent messages and I don't receive them. What do I do? Is it because of the recent update to the S8?

How do I fix my mic on my IPhone?

Recently, I was listening to music with my earbuds in until a sound started ringing through the earbuds and I immediately disconnected and restarted my phone. After that, whenever I call or FaceTime someone, the other person can't hear me but I can hear them. What should I do?

I lost my phone at my house?

Okay so here's what happened. A few hours ago, I was on Twitter going through some stuff and then my dog was barking at me and wanted food, so I left my phone on the couch and went to go get him some food. I totally forgot about my phone because afterwards my dad came home and he wanted me to help him with a few bills that needed to be payed. Around 30 minutes ago, I went to go find my phone on the couch to see if anyone has texted me, needed to be charged, etc. I looked everywhere in the house. The couches, the tables, behind the tv, almost everywhere. I couldn't find it. I went inside of my room to see if I can locate it and it wasn't there. I live with my family but my siblings are all at work and I'm the only one with my dad. He obviously didn't take it because I was helping him most of the time. I looked in every other room and still couldn't find it. Please help? I have an LG Escape 3 so I don't know if there are specific apps for these types of phones. I totally think it's unfair for Apple to have Find my iPhone but Androids can't have their own app.