I received a gaming computer for Christmas, downloaded everything, but I can't find it. It's not in the normal place. I can't find it anywhere. I've looked. I can find "electronic Arts" but no the file extension that has your "mods", "saves" etc.

Assuming your new computer runs Windows, the game uses the environment variable USERPROFILE to locate the Documents folder where it creates the "Save Game" folder, if you start the File Explorer and click on Documents under This PC you should see the Electronic Arts folder, you will need to run the game at least once before the folder is created, it doesn't contain a Mods folder by default, you will need to create that one yourself.

If your language is not English the above folder names may be different.