Well, I have a touch of bad news for you, the fuel light will NEVER work unless you wire it up. As far as I know, it was never connected on ANY of the trucks shipped to the US.
That being said, we now need to get the trouble code that is causing the 'check engine' light so we can diagnose it and get you on your way. Under your passenger side dashboard (hopefully you don't have A/C, that makes things harder) is a small brown box marked "Land Rover Diagnostic Display". It's about the size of a cigarette pack, and just to the left of the main ECU.
That box is semi-transparent. With the ignition switch on and in dim lighting you should be able to read a 2 digit code through the side of the box from the red LED's inside. Once you get that number you can either check the FAQ section for what it means, or check back with us here and we can point you where to look next.