u/areyousakethin r/Kotlin • Recommends
On “Where did you learn ktor from?”
Documentation is perfect imo.
You can also check out Nate's yt playlist (has only 2 videos as of now but pretty good to start) or Phillip's single shot tutorial for getting started and the official Kotlin channel have few tutorials around ktor and there are also few talks around ktor on yt which may help you to get started:)