Like in wow, can you?

Like your skill points spent.

not every day like wow, you need a reset stone ( for each class if you f*cked up both)
Cash shop item, 2kinds: one for low lvl, and one thats more expensive works till 50.

If you think you skilled wrong, wait till 45 (?) because you get at least one for free from your bag.
If they alter skills you might get 2 for free (happend after the end of the open beta)

On the other hand, you get tons of TP to push all skills

Like Hell Knight said, there's a reset stone for 15 and below, and one for every level. You get a free reset stone at 30, but that's only for one class.

You continue to gain TP even at 50 though, so its possible to eventually max out every ability. Skills cost relatively littly TP before 30-35ish however, so if you're still low level, I wouldn't worry about it to be honest.

2 free reset stones by the time you're 50. each there after will cost you Diamonds.

That being said, when they do the upcomming class balancing ... 2 months off ... they will likely give each character (10+) a reset stone. On release i had 4 stones on some chars from balancing issues.