If you want to trade x for y, it means that you have x and wish to acquire y. To take the classic Settlers of Catan example, if you have wood for sheep, that means that you have lumber which you wish to exchange for someone else’s livestock. You can make “for” work in the opposite direction by saying you wish to receive sheep for wood, but please do not let this advanced example confuse you.
Q: How about WTT STICKS 4 STONES? That’s “four” not “for,” so it means I have the rocks, right?
A: I will end you and all you love.