I have just signed for a job, but i want to back out...

i have just signed job contract, can i still withdraw from it? I thought over the salary I am about to receive from them against the expenses i would incur in one month's time and i realized that the expense is higher than the salary, while still bearing the hard even miserable situation of bedspacing in apartments in the city. So I have to back out.

But would the employer allow me to do it? Can i just do that?

I have been told of the salary I will be receiving beforehand and I accepted it because it is higher than the salary i used to receive from the jobs I held in my province where I am staying now. I have always wanted to work in Manila becuase I think there are many opportunities there, and because it's been hard too looking for a job here in our area. But now, after asking prospective landladies and computing for the most frugal budgets I can do to my meal, transportation, and expense for basic hygiene, I realizd that my salary can't cover that.

Now I have decided to look again for a job here in our area where i can earn more but less connected to my education. Or to go abroad like taiwan to work as a factory worker.

I have to accept that my dreams about succeeding in Manila is a very faint vision.


So now, back to the topic, how can i tell the employer that i am backing out? it's actually on friday that i have to report there for training which is also the start of my employment with them. I have one more day left to tell them, and i actually just decided tonight.


Help. would I have a very negative impression on them doing that, supposing that they don't understand fully my explanations, (because i am not good at talking)
would they blocklist me for doing that?