Some things can be upgraded, some things can't. The processor can be upgraded to what the motherboard allows, and often, the processor is already as big as it can be. In addition, with a laptop, increased heat from a larger processor may cause serious problems.
I'd start looking at the website of the company that made your laptop. Then, I'd find out what kind of motherboard it is, and what processors it supports. You can use a utility like Everest or Belarc Advisor to find out more about your equipment.Everest infotoolBelarc