For Swift: https://www.apple.com/swift/playgrounds/ (I've had more success introducing programming with this than with any of the links below; it's a very compelling intro for those who already own an iPad/Mac, and the core concepts are generalisable to other languages/environments even if it's specific to Apple's APIs and hardware.) ~~~ For Python: https://automatetheboringstuff.com https://nostarch.com/big-book-small-python-projects ~~~ For JS: https://eloquentjavascript.net (project-based and for beginners) https://javascript30.com (not for total beginners or self-study, would need a friend/tutor)
Also recommended in this reply