Started out with console screen says Service Theft System tried to save by resetting computer?

At first the Services Theft System code allowed me to start and use the vehicle with only my speedometer and tachometer working but the fuel and temperature gauge had no response whatsoever. I tried to reset watched YouTube mechanics and now it's worse no start nothing. The rest is as follows:
I left my battery left disconnected for a day, then reconnect and double check every connection, fuses, battery fully charged. When I turn the key I have inside lights that all the instrument panel doesn't light up. doesn't crank or turn over and I double checked everything again. I'm frustrated and puzzled can't use or start the vehicle key doesn't come out of ignition unless I pressed release tab under the steering wheel column to take key out but it the same every time I insert the key. Can you please help me I'm stuck in this matter alone?