I Turn on the ignition key and nothing happens, no lights no horn nothing

was the ignition switch / key flashed to the vehicle

Try another battery. Sometimes a battery might have enough amp to turn the lights on, open and close the windows, and even beep the horn. Sometimes it might even display that it have the right amp, but in reality the battery is damage giving you the wrong information.
Test with another battery, you could borrow one from a friend. Being there, done that.

Is there an immobiliser fitted to the vehicle that the new key needs to be programmed to?

ignition relay control need to be looked at. it under the dash near to the bottom of the dash speedo etc. you need to take the cover off the foot well and put your hand up and un clip it they leave enough wire so you can un plug it from the foot well.

i need more info. could be a bad ignition switch

crank position sensor is bad

It there is a problem with the dash, there is probably no power to the anti theft module in your ignition. The car is in anti theft mode due to not being able to read your key transponder. Basically if it cant read the key, it thinks its being stolen. Either fix the dash lights, or fully bypass the security. All the security info you need is on here including how to bypass it.
http://vatspasslockpasskeysecurityhelp.yolasite.com/

If you hear a click then nothing happens then 1- Either the battery is weak. Stereo doesn't need a lot of current. You can turn on the head light and horn at the same time so see if your battery could deliver all current needed to justify the battery. 2- Or your starter solenoid is bad, its poor contacts inside could not carry enough current to the starter to turn over. If you hear nothing, everything is quite then there is a problem with the safety switch at your transmission shifter. This switch is to recognize the Park position before enabling a circuitry to the solenoid starter.

Make sure that the connections at the battery is clean and free of acid built up. Take the terminals of and clean them propperly

It could also be the ignition switch at the wiring end not making proper contact anymore, try and wiggle the ignition wiring if possible and see if there is any change in the status when the ignition is switch on