Ivan's granddaughter would like to capture the screen of an iPad and add visual commentary. Leo says she wants to be a youtube star! Leo says the iPad can't do both. It does have a built-in screen recorder. Then you can record her with a camera and then edit the two together on a computer with a picture in picture option. Another option is an open source program called OBS Studio that can do it in real time on a computer. It's mostly used in making screencasts.
David has been asked if he can help do live streaming. Does he need Wi-Fi for that? Leo says not really, but he does need a cable long enough to go from where he's filming to a computer in order to stream it. If he uses multiple cameras, then he'll need a switcher to control them. It's always best to start with one camera and then expand as he needs to.
Video capture software to do the streaming depends on where he wants to stream. Facebook and YouTube both offer streaming for free. They also offer software to download.