What smart phone should I get next?

Right now I have an iPhone 5s. I bought it last October as my first smart phone and it is pretty good. However apple products have expiration dates and mine is way past due so I'm thinking of leaving apple and going Samsung. Anything affordable (I bought this iPhone for 200$ and pay 35$ a month for mostly unlimited) yet still spacious and good at processing.

IPhone 8 Plus - how do I clear all notifications at once on the lock screen?

This is my first time having an iPhone so I'm still trying to figure things out. On the lock screen there's usually a patch of notifications that have the option to clear them out but above that there's a bunch that I individually have to swipe and press clear and that s a really big pain. Is there anyway that I can clear them all at once?

Apply ID won't work?

**MY iPHONE IS A 6+**
So I have a child's apple ID, and it works fine, (so it sends permission to my parents for the app), but my parents have Samsung phones. Except for the fact my mom still has her apple ID. Before iOS 11, it worked fine, but after it stopped working. I'll have her signed in to the iTunes option in Settings, but when we try to download an app on my phone from the app store, she keeps having to sign in again and again, and it never downloads. I tried calling apple and their only option was to make my child apple ID an adults, and I don't want to do that. Is there any way to fix it?

Optus phone trade up?

So I'm coming up to my 12 month phone trade up and want the IPhone X but I'd still like to keep my current phone and won't be able to afford to pay the rest of the phone there and then. How does it work do they add extra $50 or whatever onto my bill to pay out the phone or do they charge me the full amount I owe on the phone to the bill? Someone please explain Australian Optus users hopefully