Difference between temp agency and a work-net?

[Sala Meoc]

Are they the same thing? If not,which of those would most likely help me in getting a job? I just turned 19 a few days ago and I want something to do with my life. I am not currently in college because I don't have my transcripts from the high school I graduated from (i graduated from the Philippines) and I need that and my last college transcripts to enroll in a college here in California. Anyways, I applied to a lot of stores last year and only got called for two interview (I missed one because I couldn't make it) and went to an open house interview but was never called back for a job. Would either a temp agency or a work-net help me get a job at 19? I don't have experience. Which one of those would guarantee that I'd get a job by going to them? I really want to get a job before December, if possible.