i have a question.

how do u get skills??? (learn from some one)(skill tree)(buy)(randomly get when you lvl)
also im in charge of the exp table. im looking for a good equation for a bell shaped curve. for example a lvl 45 should have about 300-400k exp needed. wile a lvl 1 should need like 10-20. i can only get one. it has to be similar but not the same as maple story.
the equation is
ax2(+-)bx(+-)c
for example
5x2 + 5x - 25

its simple algebra. a 7th grader can know this.