“He said to get him a salad or something.”
You and your sister are ordering food from a restaurant to take home. You called your father and asked what he wanted. Now you tell your sister what he said.
He said to get him a salad or something.
You can use "or something" at the end of your sentence to show that you're flexible, and you don't mind if something different happens.
For example, you can say this if you're thinking about getting a pet dog:
I think I'd like to get a Labrador or something.
This means that you would like to get a dog that's similar to a Labrador, but you won't be upset if you get a different breed instead.
This is a way to report one person's commands or requests to another person:
He said to wait for him.
This means that someone told you "Wait for me" or "Could you guys wait for me?" or "Hey, don't leave without me, OK?"
Here's another example: imagine that you're a child. Your father told you "Don't talk to strangers!" Now your brother is about to talk to a man who he doesn't know, so you remind him of your father's words:
Daddy said not to talk to strangers.
So you can see that the pattern for negative sentences is "(someone) said not to (do something)".
The pattern "get (someone) (something)" means to get some kind of gift for a person or a group of people:
I got her a birthday present.
She got us lunch.