Hi there!
I guess, the right answer depends a bit on what you already know, in which direction you want to learn and what you need this for:
• Do you know any language and/or technology and the concepts behind it?
• Do you already know Java? Then the kotlin-course in the channel-info might be for you.
• Complete beginner with programming? (beginner kotlin-courses:
https://www.coursera.org/search?query=kotlin&productDifficultyLevel=Beginner&sortBy=BEST_MATCH)
• Is this for your studies, work, hobby-project, or ...?