"jano" is pronounced incorrectly here, it should be pronounced with a short "a"-sound as the "u" in "upp". - native finnish speaker
I'm even confused how a native speaker could make this mistake and the others not notice.
But the English "u" sound as in "but" or "lunch" does not exactly match the Finnish "a" sound.
Would the literal translation here be "Joni, I have thirst"?
Yes! But even more literal it would be "Joni, on me is thirst".
It's like "I am hungry = Minulla on nälkä (On me is hunger)".