Wireshark Training

Here is a link to free Wireshark training  to get you started sniffing packets This is a great blog to get you started you will learn Wireshark from the scratch. 

They will show you the
menus, filters and many other options. Most of the people know about Wirehsark,
but they don’t want to try it, because they simply don’t know how to write filters. One  focus will be on creating filter, not writing filters. Yes it is true,
that you can make filters without learning those filter parameters. On simple
words, you can use Wireshark without touching the keyboard. Those who have kali
linux, they have it in Kalilinux. I’ll be using wireshark 32 bit version. I’ll
concentrate on HTTP traffic throughout the tutorial. So let’s start with little
bit of theory.

You can also run Wireshark on almost any operating system. 

To download Wireshark go here:
 https://www.wireshark.org/download.html

To take the training go here: 

http://pentesterblogs.blogspot.in/2016/10/jumpstart-your-wireshark-skills.html