Your first real paycheck shows who you were all along: saver, show-off, giver or ghost.

Money does not change people so much as remove the constraint that was hiding them. The first time there is a surplus, whatever you would have done all along becomes possible, and you find out fairly quickly which way that runs. None of those four is a verdict on your character, though each is useful information about what you reach for once the pressure lifts.

Watch where the first spare amount goes without judging it, then choose on purpose where the next one goes. One deliberate allocation, even a small one, is enough to start setting the pattern.