Which type is the pokemon really?
Ex- is golem rock or ground?
Yes. For example, Chandelure is considered a Ghost type with a secondary type of Fire.
Here is the page for Fire types. At the top is a table where you can press all types. Scroll down and there will be another table, where you can see a Pokemon's secondary type.
http://bulbapedia.bulbagarden.net/wiki/Fire_(type)
Golem btw is a Rock type with a secondary Ground type.