Firware_Install

my phone is samsung s5 sm-g900f. My phone have some bugs. and i want to install anoter
firmware. i install Phone Info.

the different informations:

Product Code : not active
Original CSC code : XAS
Active CSC code :XAS
PDA version : G900PVPU1ANE5/ G900FZHU1AND1
CSC version : G900FZHU1AND1
Baseband version : G900PVPU1ANE5/ G900FXXX1ANE5
Android version :4.4.2
Mobile operator : 61203
Country CSC : USA/ US


i think that my phone is unlock
but imei and s/n are changed
and s/n is 00000000
product code is not active , has it any problem? presently i am in IVORY COAST

when i triy this : *#06# , i receive : 35************/ G900FXX1ANE5. Can you help me ? what is the best firmware for my galaxy s5?
Please help me