Jupiter is a giant ball of atmosphere; there's no ground as you would imagine it. There's nothing to land on - trying to land on Jupiter would result in you going deeper and deeper until you are either crushed by the pressure or cooked by the heat (it gets warmer as you go into the atmosphere of Jupiter just as it gets warmer as you come down from the mountains on Earth, for the same reasons).

It might be possible to build a balloon or something that could suspend itself in Jupiter's atmosphere where it would be habitable, pressure and temperature-wise, but we don't yet have the technology needed to do that. Also, Jupiter's atmosphere is mostly hydrogen and helium - we wouldn't be able to breathe.