Yes, this could happen to you. You might forgot your password. Yup, lots of password to remember, many of us living in this digital age do.
Things to do
1) Go to your wp-admin and retrieve your password. (and make sure you set a strong one here, alphanumeric symbols combination would be best)
2) If your WordPress site is hacked, and all the usernames and email are changed, then you will need to reset your WordPress password from phpMyAdmin.
Here, we will be using cPanel to access your MySQL Database, then browse it via phpMyAdmin.
Once you are in phpMyAdmin, you will need to select the correct database on the left hand side. Look for the name that you found in your wp-config.php and click on that. You will see a list of tables with a prefix wp_ for the most part. (note, you might have change the wp_ to wpk9_ during installation, if this is the case, just follow wpk9_ or whatever you have changed)
You will look for the table wp_users, click on it and then click on the Browse Tab.
Click on the Pencil (Edit) Icon to reset your Password.
Edit the user_pass field value. You will notice that there are a lot of random characters in the password field. Due to security reasons, WordPress stores the passwords as MD5 Hash rather than Plain text.
This means that you will not be able to enter plain text as the password. You would need to use one of the MD5 generators online to generate your password.
Simply type your password in that tool and generate MD5 results. Copy and paste the code you get from the converter into your phpMyAdmin field and click Go to save changes.
You have now successfully changed your WordPress Password from phpMyAdmin.