When you are using the Linux operating system, there are a variety of distributions. This means that there are different ways that people have chosen to package the system with a wide variety of different applications. What can you do if you do not like your distribution's application base?
For most distributions, it is easy to install software. Many have what are called repositories that you can search in to find and install software that you would like. If your distribution changes software on you to new applications that you aren't too fond of, generally the old ones that you liked will still be in the repositories for you to use. Simply search, download, and install the ones that you like.
If your distribution does not have repositories, typically it's easy to find and install open source software from other locations. If this sounds too complicated, you might want to switch to a Debian based distribution like Ubuntu since all the compiling has been done for you.
Sometimes you have completely different applications because you are using a different graphical user interface. Most use either Gnome or KDE. Each of these comes with their own applications like editors, calculators, file management systems, system tools, and administrative settings. If your new distribution doesn't look anything like your old one, it might be because it's using a different GUI. Change from Gnome to KDE or to another to get a different set of applications. You can always install KDE application in Gnome if you like those better but don't want to use the KDE interface.
Many times applications might be left out because there is no more room on the disk which is generally limited to 700 megabytes. You need to learn the skill of finding and installing Linux software as when you switch or upgrade old tools that you might have been used to might no longer be there because of the limited space.