go (do something)

In casual speech, you say "go (do something)" to mean "go (somewhere) and (do something)". For example:

Do you want to go see a movie?

I need to go get my prescription filled, so I'll be back in a while.

grab (something) (from somewhere)

In casual English, you can sometimes use the word "grab" to mean "get". In the example above, the mother asks her son to "grab some pasta sauce". That doesn't just mean that she wants him to hold onto the jar. It means that she wants him to get it and bring it to her.

Here are some other examples of "grab" used in this way:

I'm headed out to grab some lunch. You want me to pick you up something?

Jason, go grab your sister. I need her help with this.

Use "from ___" to tell where the thing that's being grabbed is:

Can you grab my screwdriver from the drawer in the basement?

One other point: "grabbing" something means that you get it quickly. If it's going to take a long time to get something, you don't use the word "grab".

a jar of (something)

A jar is a glass bottle with a wide opening at the top. Pasta sauce is sold in a jar in the U.S.

the next aisle

An aisle is a space in between rows of things, like between seats or shelves. Most stores have aisles with different types of items on each aisle.

In the example above, "The next aisle" means "the aisle next to this one". It doesn't necessarily mean the one that you're going to next.