Pkease please please help me!!! I will give u five answer props if u do!!

I want to get my book published, like really published, not on a website. But i dont know what to do!! I know i need an agent, but how do i find a good, knowladegeable, trustworthy one?? And im afraid i wont be taken seriously because of my age, but im confident in my writing ability, and my friends think i should go for it. Someone please help me!!!