I only subscribed about 2 days ago after coming back to WoW after 6 years. The game has changed so much since I left right around the Cata release. I decided to start fresh on a new server. I still had all my old links and logins to places like Curse, WowInterface, etc. Loaded up all the addons I had favorited years ago (of the maybe 1/3rd that were still maintained). Got to level 20 in a few hours of playing. Had to look a bunch of stuff up.
A few years ago a wow promotion came out that gave you a FoS for leveling a character from 1 to 20. So i started leveling a Horde rogue since i'd never played Horde (and i've played since vanilla), and the fun I had experiencing the "other" side was super fun and nice and I actually saw a lot of cool stuff and actually sorta-kinda got that old "vanilla" feel of exploring things for the first time.
Level your hero. You need to start leveling him from the moment you have 2-3 units. This isn’t necessary. If you have KotG, DH, BM, FS, or AM you don’t even have to wait for units. However, with the help of units, your hero can very easily overcome creeps. Among players there is a certain understanding – creeping. Creeping is the destruction of neutral units in order to gain experience. If you kill a creep you earn gold. A gold number and a plus sign will appear on the screen. Sometimes, you need to kill them in order to earn more gold for building purposes.