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.)

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For Python:

https://automatetheboringstuff.com

https://nostarch.com/big-book-small-python-projects

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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)