If you have already created your user, you might have created your user with the wrong password.
So drop that user and create another user by doing this.
To see your current users.
SELECT Host,User FROM mysql.user;
To drop the user
DROP User '<your-username>'@'localhost';
After this you can create the user again with the correct password
CREATE USER '<your-username>'@'localhost' IDENTIFIED WITH mysql_native_password BY '<correct password>'
;
then
FLUSH PRIVILEGES;
You might still run into some more errors with getting access to the database, if you have that error run this.
GRANT ALL PRIVILEGES ON *.* to '<your-username>'@'localhost';