Q:

Could you simplify "you are going to" in this context, although I know the use and meaning of this grammar

So today we're here to talk about the two second rule. And what the two second rule is, is a way of you to know whether or not you've got proper distance between yourself and the vehicle that is traveling ahead of you. And what you do with the two second rule is you pick a standing object on the roadway. So let's say you're going to pick a tree, which might be right here. Or an overhead sign. And what you do is, you watch the car ahead of you. And when the car ahead of you becomes even with that object, whether it be that tree or that overhead sign, at that point you start to count to yourself to two seconds. 

I need to explain this to someone who is a beginner and does not know the grammar use of that. A simplified equivalent I need. 

A:

The phrase "you're going to" has two meanings that I can think of:

The first is that you are going to a location in the future, or currently are going:

"You're going to the fair? Me too!"

The second is that you are about to do something in the future:

"You're going to eat an apple."

As with lots of things in the English language, it depends on the context. Consider if the speaker is talking about a location, or an action.

