Has anyone ever been to Jupiter?
No people have ever traveled to Jupiter. It's too far away. At this stage we're not even thinking about trying to send astronauts that far away from Earth—we need to get people to Mars or perhaps an asteroid first.
Even if we do eventually get people to Jupiter, there will be many challenges. You can't land on Jupiter because it's a gas giant planet, the atmosphere is very hostile with constant stormy conditions, and the whole planet is surrounded by intense radiation.
Some of the moons of Jupiter would be better places to go. They all have a solid surface, some have potentially useful resources, and some of them are relatively clear of Jupiter's radiation. Deciding which moon to set up a base on would involve weighing many pros and cons. It will probably happen one day, but not for a long time.