I like learning through games, because it helps keep me engaged. BitBurner is a free incremental JavaScript programming game that I enjoyed. It even has a coding puzzle element similar to games on codin game.com, which has a bunch of free games/puzzles in several languages.
These games didn’t necessarily walk me through programming concepts, but got me comfortable with reading documentation and a offered a sandbox to experiment in. YMMV.
http://txtify.it/