There is nothing to unlock in RFC. its an lowlevel instance (13-20) You can run it with friends or the LFG system for loot and exp.
Currently, the lowest level dungeon in World of Warcraft is Ragefire Chasm (RFC). You must be level 9 in order to get in there, but you must be a little higher if you are an Alliance character as the minimum level is 15 using the Dungeon Finder, which is the only way to get there as a low level alliance, unless you are lucky.
The hardest raid is no longer ulduar, the hardest WoW raid is Trial of The Grand Crusader 25 man heroic raid.
You can train on Npc's or you can quest. Also once you hit level 10 you can ask a friend to take you through Ragefire Chasms (RFC) and you level fast, ask for other instances and raids. It's an easy way to level but you can also stick to questing and fighting npc's. (ragefire chasm is horde only! if you are level 10 and alliance you'll need to get up higher level from quests to atleast 15 for deadmines)
what is a chasm
I pushed your baby into a chasm.
It is called the chasm.
The Chasm is in Prestos Edge. To get there, walk to the right until you see the chasm with a bridge going over it. Use your levitation power to hover over the chasm and let the levitation power run out after a few seconds. You will fall into the chasm.
The Grand Canyon is an enormous chasm.
The Giant Chasm is North of Route 13.
Crossing the Chasm was created in 1991.
Chasm City was created in 2001.
Cosmic Chasm was created in 1982.