To install applications to your new server, simply type the following (where <your application> is the name of the application you want to intall:

apt-get install <your application>

For complete details on the options of apt-get, use the man apt-get command.

If, after typing apt-get install <name of application> you get the message:

Reading package lists... Done
Building dependency tree
Reading state information... Done
**E: Couldn't find package** <your application>

This means that you either made a typo in the name of the application, or that it can't be found in one of the repositories listed in etc/apt/sources.list on your server.

A quick web search will usually tell you which repository you need to add to the sources.list file in order to fetch the package you're after. You will then need to edit the sources.list file (with Nano, for instance) and add a new line for the repository you're adding.

Once this is done, save changes and enter the following command:

apt-get update

Once this has been done, you can retry the apt-get install <your application> command, and if the application indeed was in the new repository, it should work.