Here is how to transition your iPhone to another user:
What to do before you sell, give away, or trade in your iPhone, iPad, or iPod touch - Apple Support (CA)
The new owner will need to set up an Apple ID.
How to create a new Apple ID - Apple Support
Sharing an Apple ID is a Bad Idea, and will usually only get content and notifications and purchases and security conflated.
If you do want to share content, you can set up Family Sharing.
Set up Family Sharing - Apple Support
How the cellular service transition happens depends on the carrier. Sometimes it's swapping the SIM or loading the eSIM, sometimes the carrier has to be involved to move the Android plan around. Or this old iPhone to your new iPhone. Sometimes the carrier sends a new SIM. Check with your carrier.
The existing Android phone will need to use a nano-SIM, if that's to be swapped over into the iPhone, too.
The previous reply here nicely covers transferring the SIM around.