OMG HELP!, my falcon died

[Dezaman]

hey guys, sorry to be posting to many threads my next thread was planned to be a build one but things havnt gone so well, ive had the car for 3 days and ive... ahem tested it to see what it can take and what it cant and out of all the things that could go wrong with it it wont start, i mean a crash, expected, brakes dying on me, expected, but the car just wont start at all, i red the forum about the fuel issue and after learning what the dte is i realised that 300 km's is no good for a full tank, i unplugged the battery and pluged it back in, turned the engine on and walla, all working fine, the tde actually said less now so i figure injectors or something like that in the future, i reprogramed the tape player and turned it off a little dissapointed that its gunna cost me a lot to fix the fuel issue, i left for an hour and came back to drive to work, turned the key and absolutely nothing... the starter motor wont crank at all, just silence, its in park i unpluged the battery again and pluged it back in, the inside light still works and the little bloody blinking hand is still flashing at me, i figure that might just be the immobiliser and the fault is with the immobiliser, what do i do????