2005 chevy cavalier gas gauge doesnt work goes into the temp gauge and when i try to put gas in it spills out like it is full.

It sounds like the fuel gauge sender unit is faulty, probably causing a wiring problem with other dash dials. Also sounds like you already full of fuel. The float and sender unit need checking and/or replacing.
(float in fuel tank). The fuel tank needs to be drained completely to do this work. Is it something you can do ? If not, it's not a major operation for a mechanic and the parts are cheap. Good luck... Red.