The basics, huh?
Scripts are special text files which tell the game engine which actions to perform and how to perform them on any given entity, or on the game itself. These scripts are located in the "sciptbank" folder of the program directory. To use a script on an entity, you simply assign a script to it by selecting one from a drop-down selection box in the editor. The entity options, including which scripts it will use, will appear on the left side of the editor whenever the entity is selected.
To place additional scripts in the program, simply add them to the "sciptbank" folder.
For more on scripting, please see
this and
this resource.
Welcome to the forum and wonderful world of FPSC game creation.
Brian.