One, here are two lists of online games to teach coding, first list is for CSS, other is for WebDev. Frankly, I've bookmarked them for myself, they look so cute.
Two, why not set your kid up with PyCharm, and start dabbling together with Python. (like build a simple chatbot or something that pulls stuff from Wiki).
https://www.tynker.com/
https://studio.code.org/courses
https://codekingdoms.com/
https://codecombat.com/