Noob iPhone Questions

I just got my very 1st iPhone today. I've been an Android user for the past couple of years so I'm still adjusting to my new phone. Here's a few things I need help with at the moment.

1. Can you turn off the auto screen rotation?

2. Does iOS feature what we Android users call a power widget?

It's an app for quick access to WiFi, Mobile Data, Screen Brightness, Bluetooth, and so on... I know iOS doesn't have widgets but is there an app with a similar functionality?

This is it for now!! I might update this post if I run into other difficulties.

Update:

3. Does iOS have an option informing you about what's draining most of your battery? It's a very useful Android feature that I may need once in a while.