The truth is, you would need many tools to do it. Advanced tools. If you want to learn it, it will take months. And you will need money to buy these tools and to learn from these hackers.
Nowadays, FB has 2 factor authentication so you don't just need an email and the correct password. You need more. This is the difficult part.
The detailed explanation is long. But you can try finding one of these combolists where there are emails:passwords and try inputting them one by one in FB. Eventually, you will find one account that has both the correct email and the correct password. But before you start celebrating, pls know that you won't be able to access it anyway because they'll detect that your IP is a never-before-recognized IP and you're not signing in from a device that FB recognizes that is associated with the account you're trying to access. So, it will auto-block you and send a notification to your email or phone.
EVEN when you have access to the email account too, they will block you from accessing your FB. I can't remember how, but that's happened to me before when I did this several months ago. I think the owner of that account had phone authentication. Basically means I was not able to get through.
Hacking FB and Hacking Gmails isn't what it used to be. They're much more secure nowadays than they were 5 years ago, when most people had not yet activated 2 factor authentication.