Bella, if you google that address, don't you get a LA Fitness place?
http://www.lafitness.com/app/club/cl...ate?stateId=CA
Scroll down to Van Nuys (though it does say 5990 NORTH Sepulveda, but it has the same zip code)
Kind of fishy. Anyways, best of luck... I'm personally not the kind of person that would go on a reality TV show, but hey, it is a once in a lifetime opportunity, if that's what you're looking for.
EDIT: Actually, maybe 5990 Sepulveda is a large shopping center/mini-mall kind of place, with different suites. It looks like there is also a deli at that address and something called Lowes Enterprises:
http://losangeles.citysearch.com/profile/307697/
http://www.seekagents.com/California/Van_Nuys/index.php