When you turn the key on, do the dash lights come on? Then, when you turn the key to the start position, do all the lights go out?
If the lights stay on while you’re turning to the starting position, the starter or its solenoid is likely not being engaged at all. Normally those parts draw a fair bit of current, usually showing itself by those lights totally dimming.
In that’s not the case, the problem is probably is due to to an interlock not operating correctly. If this is an automatic, it could be due to it thinking the car is in ‘drive’ and not in ‘park’. Try moving the stick to Neutral and see it will start.
It could be something like the ignition switch as well, among various other things, though.