It is not a natural language, it is a constructed language. It was created for a fictional race of aliens (called Klingons) from the Star Trek TV show and movies). There are speakers in many countries, but no country has a particularly large concentration of speakers and there are no native speakers. The practical uses of the language are very limited, but it is a fun hobby. For people who have already learned natural foreign languages it can be a fascinating exploration of language alternatives. For someone learning their first non-native language it can be a good introduction to the topics and processes needed to learn more foreign languages. And if they are a Star Trek fan and this is the motivation they need to start learning about languages, then it makes a nice introduction. Check it out and see what you think!
Be careful of your spelling. Notice the difference between I and l (one has a curl at the bottom). The l belongs between the t and h and the vowel that follows is an I: tlhIngan. Also, that refers to a person that is Klingon. To make it about the language, you have to add the word for "language": tlhIngan Hol.