That's really up to you. It's your flaw.
Since flaws grant XP when they hinder you in some meaningful way, how complete or severe it is will likely have some bearing on how often it comes up. That said, you only need it to come up once in a "chapter" to get the 1 xp.
(The system -- at least RAW -- limits it to 1 xp per chapter, to keep players from having a flaw that always comes up and thus swimming in XP.)
Alright, adding the Vampire template...
Clan is Mekhet.
Favored Attribute: +1 dot in Intelligence or Wits
Disciplines: 3 dots, divided as you want between Auspex, Celerity, and Obfuscate.
Merits: I'll give you 4 dots, of which at least 3 are to be spent on Vampire-specific merits -- including Haven, Herd, and Status (although Covenant status will be limited to 1 dot).
- There are other vampire-specific merits, and you might look up things specific to the Mekhet or your Covenant (if you decide on one).
(I have most of the books, so if you have something in mind you can ask and I can see if there's anything that fits. Or you can .pdf hunt. Lol)
Blood Potency is set to 1.
You can also sacrifice a dot of Humanity for 5 xp to spend as you wish. You can do this twice, for a total of 10. It is completely optional however, and losing humanity can result in derangements. Your choice.
Edit: If it worked, I edited the template part of your sheet to add some headers and basic information. You should have your type (vampire), clan (Mekhet), power stat (blood potency), three clan disciplines, and a few other things filled in. Hopefully.