Where do I find my Apple ID?
1.Tap Settings > [your name]
2. If you're already signed in to your device and you see your name at the top instead, tapping on your name will take you to a page that displays an email address bellow your name. That email address is your Apple ID.

How to check if you have the latest version:
The latest major version is iOS 13
1. You can check which version of iOS you have on your iPhone, iPad, or iPod touch via the Settings app.
2. Open Settings > General > About.
3. You'll see the version number to the right of the “Version” entry on the About page

How to update to the latest version?
You can upgrade iOS to the latest version available for your device from the Software Update screen. Your iPhone, iPad, or iPod touch may occasionally show a notification telling you a new version of iOS is available, too.

To start an update, head to Settings > General > Software Update. Your device will immediately check for an updated operating system. If an update is available, you can download and install it whenever you want. Tap the “Download and Install” option at the bottom of the screen to install it.
If no updates are available for your device, you’ll see a “Your software is up to date” message instead.

Why can't I update to iOS 13?
If your device tells you your software is up to date, but you aren’t running iOS 13 or iPadOS 13.1 yet, you’re probably using an older iPhone, iPad, or iPod Touch that Apple no longer supports current operating system updates.

According to Apple, the following devices are compatible with the iOS 13 operating system:
iPhone: iPhone 11, iPhone 11 Pro, iPhone 11 Pro Max, iPhone XS, iPhone XS Max, iPhone XR, iPhone X, iPhone 8, iPhone 8 Plus, iPhone 7, iPhone 7 Plus, iPhone 6s, iPhone 6s Plus, and iPhone SE
iPad: 12.9-inch iPad Pro, 11-inch iPad Pro, 10.5-inch iPad Pro, 9.7-inch iPad Pro, iPad (7th generation), iPad (6th generation), iPad (5th generation), iPad Air (3rd generation), iPad Air 2, and iPad mini 4
iPod touch: iPod touch (7th generation)