Downloading???

[Ray Gordon Smith]

I AM TOTALLY NEW TO LINUX AND HAVE NEVER USED A LINUX OS BEFORE PS3, IV 
ONLY USED WINDOWS BEFORE, WHAT I NEED TO BE EXPLAINED TO ME IS HOW TO 
DOWNLOAD CODECS LIKE REAL PLAYER, QUICKTIME, FLASH, ETC. EVERYTIME I TRY 
TO DOWNLOAD I GET SOME KIND OF ERROR MESSAGE OR THE DOWNLOAD 
INSTRUCTIONS TELL ME TO WRITE SOME KIND OF COMPUTER SCRIPT IN A 
"TERMINAL" WHAT IS A TERMINAL?? AND HOW DO I FIND IT??? CAN SOME HELP??