1- How can I get the update (does it show automatically?)
VectorLinux has a different packaging system to Ubuntu and Fedora. It is suggested you read the VL Manuals, especially the gslapt and slapt-get manual that can be found via the VL Docs icon on your desktop. Updates do not show automatically. You run "gslapt" and the Mark all Upgrades, and Execute to update all packages for which there are newer version. However
in the Slackware world, doing full system updates is not relly recommended. Such manoeuvers are fraught with problems (on many distros, icnluding Ubuntu). VL and Slackware are very stable secure systems and the only reason to upgrade is to upgrade an individual package for which you require more functionality, to fix a bug or to close a serious security hole.
2- How can I install a package that I downloaded from another sources?
It will need to be a Slackware v12 package or a VectorLinux package to be sure it works well. Then you use the "installpkg packagename" as root in a terminal to install it. To install from source you would be best to use the "vlpackager", in your system menu.
3- where can I get tsclient package for vectorlinux?
First run gslapt and enable the extras repository, if it is not already enabled. Then run "Update". Then search to see if there is a tsclient package. If there isn't try getting a tsclient package at http://www.linuxpackages.net
. If none there, make your own package from source using vlpackager or make a request here on the forum to have one made for you.