If it is just spinning and not throwing out you could have a starter issue, bench test if this is suspected.
If it is throwing out, you could have damaged ring gear teeth. Remove the starter and manual turn the engine over by the crank pulley, inspecting the teeth as you go.
If it is not responding when the key is turned, you will need to check all fuses and relays in those circuits. There may also be an issue with the ignition switch or damaged wiring.