Honda Civic ex 1996

Check for corroded or loose battery cables. If everything checks out good, check voltage at the solenoid

cables are good. How do you check voltage at the solenoid??

First check voltage at battery, minimum 12.4vdc. If voltage is good at the battery, have someone try to start it and you, with a meter check voltage at the starter solenoid small terminal. If there's 12 volts dc present when you're trying to start it, replace starter. If no voltage present when you're trying to start it, check starter relay