I removed the link to the website in your post as this site is not to be used to advertise other websites.
Learning Klingon takes as long as learning any other language. It totally depends on how much effort you put into it. If you only study it once a week, it might take years. If you spend every waking hour of the day studying it, it may only take a few weeks.
qurgh Answered question June 14, 2018