Download the addon Questie. You can download an addon manager (highly recommend WowUp) which will automatically install addons in WOW Classic TBC Gold the appropriate folder for you and inform you when they need updates.
Questie will tell you which quests that are appropriate for your level for your particular faction are all over the world. It will also show you where to locate the minimap and map objectives. As you progress into higher levels, traveling to the other continent or to other areas which aren't readily apparent become essential for a seamless leveling experience. I can guarantee you that there will be quests appropriate for your level in the game, you just might not realize where you are. Questie greatly assists in this.
In addition, The weapon you use is extremely crucial. If the weapon you are using is several levels below, you're likely to be struggling to kill the appropriate level of mobs. Even so, taking on multiple enemies at the same time is always going to buy TBC Classic Gold be a difficult task in the Classic/TBC. It was designed this way to make the leveling process more engaging in general, however it can be frustrating to players who don't have the right mental state of mind.