I want to add a light, switch & receptacle at a end of line receptacle. How do I got about it?

Well to start with, you have to know that the circuit you want this on will be able to handle the additional load.

Then you have to figure out how you are going to source the feed for the circuit extension.

I would bring the feed to the receptacle outlet. Then, I would feed the switch with the black conductor. The white conductor will by pass the switch because switches do not use a Neutral connection.

The I would feed from the switch to the light.

I would do this with the circuit powered off at the breaker.