Welcome to linux, falcon. It can be a little bit of a steep learning curve, but once you are past it - there is no turning back, i promise :-).
Firstly, you have to let us know a little bit more about your system. Every distribution of linux is different and runs in a different way.
For example, mandrake, redhat and suse all have different ways of using rpm packages.
Meanwhile, if you want to update your kopete, you can either get a package from your distributor or compile from source.
For a beginner, you would only ever need to compile from source if you a package wasn't available.
Hope we can be of help, but first we need to know more. (Mainly distibution and release - eg I use suse 9.1
-- seb