I´m kind noob here...i have a lvl 20 magician wut do i do to find good stuff::??

keep leveling. Theres no real trick behind it... mostly dumb luck
leveling in the catacombs with a party does increase the drops rates though

Slash and Slash, if you can try and beat the well monsters by adding a white item to the well [however he is very hard if you don't have sufficient gear], if you find good prefixed items [Arcane,Epic,Mythical,etc] you can try you're luck and transmute them with another one alike to gain a better one hopefully.