I snooped around and GCC is described as a Traditional Chinese, born-again Christian college - very strict (no proms or school fairs) and expensive. It's likely that the students wouldn't be your average happy-go-lucky Filipino but rather more similar to your Taiwanese/Chinese students who love tests and memorization
You might be surprised that they speak Fukien Chinese and not Mandarin Chinese (they study Mandarin but don't use it at home.) I don't even know if this school accepts pure Pinoys or just citizens with Chinese blood... The Chinese/Filipino-Chinese community keep to themselves and look down on Pinoys most of the time.
The school is in Quezon City (QC) and it's quite far from Manila (capital), considering how long the commute would take (at least 1.5~2 hours). But it's part of "Metro Manila" (http://en.wikipedia.org/wiki/Metro_Manila
) which is comprised of Manila, as well as other cities - QC is the largest. If you look at the map in the link, I believe the school is near the "Caloocan (North)" area. Not much to see or do there, or within Metro Manila for that matter. There are lot's of huge malls... so that a typical weekend for the family would be going to the mall on Saturday, and church on Sunday. Traffic is really bad so it would be better to live near the school.
If it's only for the summer, it'll be a new experience and I'd say go for it. There's poverty and crimes, but just be sensible and aware of your surroundings - don't take out your mobile phone/cash/valuables in public, don't eat street food, don't go out alone late at night, don't talk to dodgy looking strangers, don't stare, don't confront bad drivers, and don't sing "My Way" in KTV (several people have been killed over it)... be more vigilant than usual. Pinoys turn everything into a joke (and dirty ones, more likely) so don't get offended too easily. There's a tendency to be lazy... not everyone is willing to work hard for high grades or more money, and exerting pressure will be useless. You'll also hear a weird language which is a combination of Tagalog and English, or "Taglish" and it's quite unusual to hear a Filipino speak pure English outside school/work because this is considered "showing off"
If you have more questions, just PM me and I'll try my best to help!