Hi oliver.
Rappelz have so many variations as in for class and builds.
I cant really say "pick this buildz0r cuz it's the pwnz0rsxxx"
It's all about your preferences and about what you like.
There's ... assistant build, damage dealers, summoners, pet healers, dual daggers or swords, spearmen, dark magician, tankers....
and three races (which names i cant recall atm, barely remember Gaia-cuz it's the one i chose for my Kahuna).
Whenever you make your char, you will have to play in group, grind with people or at least with a couple, so you both back up.
Quests aint that good, most are like "go kill 90 mobs of these, 80 of these, and 70 of these, then come back" and the next quest is pretty much the same. There are some interesting quests, like going and kill raid mobs, (you could say they're like unique spawns in sro).
And what i really like of rappelz it's the caves raid system.
Fill a party and grinding in there is the best you could ever do in a game

. So fun. Lots of teamplay.
uhm...
back to the character thing....
leveling a char till lv 20-30 is really easy and fast.
My advice would be, try one char for any of the three races, read about them and try to stick with one of them at the end.
Hope that helps!
Cheers.