Ac is a very complex machine , you must have to be very perfect if you want to repair it yourself, you can watch YouTube tutorial about the problem you are facing, that might help
Reinstall the access panel and disconnect block. Turn on the circuit breaker and furnace switch, then set the thermostat to a lower temperature and wait for the AC to start. The compressor should run and the condenser fan should spin. If the compressor starts but the fan doesn't, the fan motor is most likely shot.
To repair an air conditioner, turn it off, check the air filter, clean the coils, check the thermostat, inspect the electrical connections, and seek professional help if needed.