Any native speaker uses slang words. I'm sure you do too.
Beware that slang varies a lot - with different countries, different age groups, even different ethic groups within a country.
There are thousands of slang expressions. You would probably be better to search for a list.
Here are some:
http://www.effingpot.com/slang.shtmlhttp://www.fluentu.com/english/blog/american-english-slang-words-esl/
Sometimes pages like that are quite dated...
If you want to look up some words - have a look at
http://www.urbandictionary.com/
You do need to take note of the votes though - some people put words on there as a joke...