Your mass remains the same, but your weight depends on the strength of the gravity field you are in.
You weigh less on the Moon and Mars because they are smaller then the Earth, and therefore have less mass, so less gravity!
If you could stand on the surface of the Sun or Jupiter you would be a hell of a lot heavier , your weight would be greater but your mass remains the same!
Another common misconception is that vacuums suck, they don't, it's the other way round, it's the surrounding air which rushes in to fill the vacuum!
There was a flat earther on a you tube channel saying that the ISS is a fake , because they had a leek, and the station was not torn apart by the out side vacuum!
This is nonsense, the pressure difference is only one atmosphere , which I think is only fourteen pounds per square inch.
And the leek itself was only two millimeters across, it would have taken weeks to empty the station.
I think he'd been watching too many bad SF films!