How to text and FaceTime an Android user from an iPad?

You can set up Face Time calls he can answer from a web browser, but for text messages you will need an iPhone that is using the same Apple account as the iPad.

click here ➜ Create a link to a FaceTime call on iPad - Apple Support

Then he can follow the steps in the link provided by Kilgore.

click here ➜ Join a FaceTime call from an Android or Windows device - Apple Support

click here ➜ Forward text messages from your iPhone to other devices - Apple Support

Both you and your dad should install the Discord app. Both of you need to start Discord accounts. Share your Discount names with each other then search for each other and friend each other. You can now text each other, have video chats or just audio chats.

There are other apps you can use like Line or Zoom that can do some of the things but I’m not sure if they can do it all.

Join a FaceTime call from an Android or Windows device - Apple Support