Quick question, some one told me that he knows my internet protocol so how can someone get your internet protocol?

There are different ways to steal ips... one way is if you click on a phishing link that steals your browser's information like ip, your country, your city, etc.
other way of doing that is complicated; If you both guys are connected to the same server, they will use a software which tells you every ip connected to your computer like when you send a message to someone on facebook or like if you and the other person are connected to the same server in-game...

But you don't need to worry about the person who told you he knows your ip... it will be changed if you restart your router/internet... hacking someone's computer through ip over the internet is a complicated task

As long as you have a firewall, you're fine.

There are many ways to trace an ip, you can google it if you want to look into it any further, but heres a few ways

http://m.wikihow.com/Trace-an-IP-Address

The majority of the time however you need to phish or brute force your way in to find out, which is highly illegal.

Thank you