It is always better to get your Facebook account password changed every 2-3 months because hackers can easily hack your account. And if your FB account get hacked (https://getassist.net/how-to-recover-hacked-facebook-account/) somehow then you can follow the steps given below to recover it:-
- Go to Facebook.com and type your email
- Then click on forgot password
- After that enter your recovery email or phone number
- You will get a recovery code on the email or phone which you need to enter to change your password