There are couple of ways to find out your computers IP address. Here is one of them.

Method # 1 : (in MS Windows operating system)

Go to Start ►click Run ►Type cmd & Hit  Enter or Ok

Now you'll get the command prompt like in the below screenshot

Now type the command ipconfig in the command prompt & hit enter

Now you'll get the below results. The number series marked in red is your IP address. In this case it is 192.168.2.104

If  you use Mac OS or Linux versions like Ubuntu, the command is slightly different. You must type ifconfig instead of ipconfig . The process of opening  command prompt in Linux or Mac is slightly different ( I cannot provide screenshots since I do not use them at present). Command prompt is usually called Terminal in Linux & Mac.  You can usually find terminal in the Linux menu or Mac menu (equivalent of start menu in Windows).