not in the sudoers file?
 

I am trying to run a program as root and typed sudo and the program name, but for some reason the user I'm logged in as isn't in the sudoers file. How do I add the user to the sudoers file?

nvm, i got around it. Just type in the console su root and type the password to login as root.

As you've already discovered, Slackware doesn't ship sudo preconfigured as a "magic hammer" - instead, it's (properly) left up to the admin to decide if and by whom and under what conditions sudo will be used. This is pretty much a common thread - unlike some distributions of linux that are mentioned in your signature, Slackware lets *you* be in charge.

Just a FYI: to edit the sudoers file use the 'visudo' command as root.