I agree, VLC is a wonderful player for all sorts of different formats.
1. Find your pisi package manager.
2. Navigate to new packages.
3. Enter vlc in the search bar.
4. Select vlc package and install.
If these video files came from a windows ntf partition then they could be compressed
If thats the case, copy your files using a command console in su mode.
About wifi connection:
You'll need to give us better description of the problem.
Open connection manager and select "edit connection".
You'll need to match your wireless network information from your router to Pardus connection manger.
Good luck abbiya and welcome to Pardus.