iOS has gotten less intuitive over the years. It can do everything you're having trouble with, though. There's a quick settings menu that's pretty similar to the one in Android. You can get to it by pulling down from the top right corner of the screen. It's customizable with whatever settings you want [0]. There are a few other gestures; you might find this page helpful [1].
The back buttons should always be in the top left when they're available. There is also a gesture; you can swipe in from the left side of the screen to go back. There's an accessibility setting to make the buttons underlined, too [2].
Product coolness, usability, reliability, value, and customer service have all fallen off a cliff in the search for more money.