What's a good platform for independently teaching computer science and programming?
Your question is quite broad, but I think you're suggesting that you wish to tutor, and wish to tutor programming specifically.  In which case, I'd consider tools like Zoom and repl.it.
The ability to live-code alongside your tutee, and watch as the work, closely approximates the experience of sitting at the same computer.  A video-conferencing app then allows you to talk directly, and the whiteboard feature of Zoom allows you to draw on a common paper together while you analyze problems together.