You need to ask the administrators of that machine to add you, or to install the package for you, as per the policies of the site.
You should also be sure to use visudo to edit the sudoers file - it checks that the syntax is correct before writing the file. And you can use editors other than vi with visudo. It will by default use whatever you have set as $EDITOR and if you don't have it set you could do
# EDITOR=nano visudo
to use the nano editor instead.
If you have access to root, then login as root and then edit the sudoers file.
Just type
su and press enter and enter the password for root
Then open up the sudoers file:
nano /etc/sudoers
You can uncomment the following and just add your user to the wheel group
## Allows people in group wheel to run all commands
%wheel ALL=(ALL) ALL
Or you can just add the user(s) that you want to work like root by adding them under this line
## Allow root to run any commands anywhere
root ALL=(ALL) ALL