Hi there no_names_left!
Welcome to LinuxQuestions.org. To find if a program is installed on your PC, you've to open a terminal (as Gnome-terminal) and type the following:
rpm -qa | grep vi
vi, as the one used above, is an example, replace vi for the programs you want to check if it's installed. Try to learn the Linux command line well, it's going to be your best buddy, since the gui interfaces, although cute, always lack some (important) function.
You might also want to read this thread in order to understand well how programs in Linux are installed, be it from rpm packages or compiling from source code: