Post-installation Steps

MySQL ships with a blank password for the root MySQL user. As soon as you have successfully installed the database and client you need to set a root password as follows:
[root@host]# mysqladmin -u root password "new_password";
Now to make a connection to your MySQL server you would have to use following command:
[root@host]# mysql -u root -p
Enter password:*******
Unix users will also want to put your MySQL directory in your PATH, so you won't have to keep typing out the full path every time you want to use the command-line client. For bash, it would be something like:
export PATH=$PATH:/usr/bin:/usr/sbin