UNDERSTANDING THE MASQUERADE
The Masquerade is an organized campaign enforced by the Camarilla to convince people that vampires do not exist. It is the cornerstone survival strategy for Kindred. Without it, the kine (humankind) would rise up and exterminate all the undead.
The most important thing to understand about the Masquerade is how to actually breach it. In some cases, a breach is colloquially called an 'oops'. When a breach does occur, somebody involved will be punished, whether he or she caused it in the first place or not. Therefore, it is imperative that you do not, under any circumstances, violate the Masquerade, or get involved with someone outside of the group who does.
Generally, a breach consists of revealing one's vampiric powers and presence to a human. This includes, but is not limited to, using certain Disciplines, feeding on blood, regenerating, or anything else considered supernatural, in the presence of any human being. In short, if you have to act like a Kindred, don't do so when people are watching.
This should be a general idea of what not to do when living out your (un)life as a Kindred. Follow these and use your sommon-sense, and you should be OK.
WEAKNESSES: MYTHS AND TRUTHS
1. Garlic doesn't do shit. Period. Neither do 'holy objects'.
2. Holy water, or water in general, is just as useless, unless it's boiling, because really, that will hurt anyone.
3. Stakes are not that much of a problem. The only thing they're capable of is paralyzing a vampire for a period of time, and that's only if the stake pierces the heart.
4. The Sun. Biggest problem for vampires. Even the slightest exposure to sunlight will cause burns. Also, when the sun arises, vampires will generally go into a catatonic, almost slumber-like state. So yes, the myth of vampires being completely nocturnal is true.
5. Zombies and vampires apparently have one thing in common, and that's the fact that both have their biggest weakness lies in their head. A shotgun blow to the head, decapitation, or anything such, and it's game over.