I really hate to sound like a dick, but the threads are all inside of these forums. It's not any harder for you to sort by "tips" tag, and use the search function than it is any one of us. Why should we go waste our time doing the same thing you could do just to end up having to explain it because you didn't care to read the thread the same way you didn't care to look for it?
Not saying that's the case, but you've been waiting quite some time for a response, and by now you could have read a few threads to find your answer...
Anyways, the answer that you're looking for is to boot into recovery mode by holding the volume down, and power button until the recovery screen comes up NOT the LG logo, it's after that, so hold it for the continuance of the LG logo, into the next screen where it'll either bring up clockwork mod recovery, or the standard LG recovery menu. In either case, that will be the next step, and I'm sure you know where to go from there.
As to WHY you don't have a launcher...shit the world may never know. but I CAN tell you that is NOT supposed to happen, and it sounds like you have bad memory in your device, and the best thing you could do is factory restore it, and return it for another.