Hey CindySquid,
Congratulations on your new iPhone 13 and Magic Keyboard!
It appears that you'd like to use your Magic Keyboard with your new iPhone 13 and to use the Emoji keyboard along with it. We're glad to glad to provide assistance.
Pair Magic Keyboard with iPhone - Apple Support -- These are the steps to pair your Magic Keyboard with your iPhone,
Learn iPad keyboard shortcuts - Apple Support -- Even though this article is for using your keyboard with an iPad, the keys are the same for an iPhone as well. To add an emoji to the text you're writing, you'll press the globe key. You'll find more keys and steps under "Use common keyboard shortcuts".
Thanks for using Apple Support Communities!