To protect your iCloud account it is better to change the password but if you do not know how to change the password then you can follow the steps below. 

Steps to Change iCloud Password! 

Unlock your device and head over to the settings option by tapping the gear icon. 

From the new screen, tap on your name and head over to the “Password and Security” option. 

Another screen gets displayed in front of you and you need to tap on “Change password” from the bottom of the page.

You will be asked for the device passcode for verification purpose and then you can create the new password. Make sure that you create an easily memorable password. 

Tap “OK” to save. 

And with the help of the above steps, you change the iCloud password by using the iCloud change password option. If you require any further help, then you are free to get in touch with the customer support of Apple.