You can learn the basic skills at the 1st town inn there are some guys in the inn tat sell skills for each class one is a footman near the fireplace other is a Priest looking with red cape and the other is the only thief in that area, (all the skills no matter class cost 250) also theres 1 skill for each class tat drop from the mini bosses on the outside world, theres 1 more wich drops in the dungeon 1 and 2 bosses then theres one guy near the boars area who sell one skill for each class (costs 1000) then in the city of mytargas (when u advance class) u can buy one more new skill (costs 5000) and is bought by a shadow hunter who is around the slum district near the park and if u want the last skill u have to remove one of the previous skills to gain a new one (costs 7000 gold and 2 lumber) this one is bought in a sorceress whos near the entrace of the city.
I hope it helps you