I will try to explain clearly.
first enter into root mode from user mode by using command, su
then enter root password and you will be in root mode
thn type command
then you should be in sudo configuration file. At the end of the file, i mean last line, in the new line type the following command
username ALL = (ALL) ALL
where username is the username whom you want to give the permissions
first ALL is the machine name, here all the machines
second ALL is the who may run what
Last ALL is the command u want to execute, here any command.
So the username here, can run any command on any machine.
So its the superuser too.
But its not usually advised to do so. For study purpose, its ok.
All the Best.