World of Warcraft Leveling/Questing?

You can quest in any races region, actually. You will see the races merging into the same areas more and more as you level higher.

Each race has their own starter zone except the gnomes who share an area with dwarves, and the trolls that share an area with orcs. You can choose to do another races starting quests at any time; it is quite a run there are your level though! Most people either roll another character to see all the starting zones, or go there at a higher level to get reputation from doing quests with whichever particular race.

Warcraft is pretty good about sending you to the next level of area. When you are done in Coldridge Valley, it will give you a quest to follow the path to the next quest hub, Kharanos.. When you're done there it will give you a quest to go to the next highest-level area.

Before you get too far in to the game, you should stop now, delete your gnome, and roll a horde

YOu can do those for a low amount of xp.