How to start performance testing

I have taken as an example for learning and gathered some information about tools, objectives,scenarios, but i need your inputs. Please assist me. I am new to Performance testing and would like to test the following website www.volkswagen.co.nz.

Can you tell me, what are need to be tested? what are the scenarios and activities for each scenario? what metrics i need to add?
which is the best and free tool for testing it? How to test if it is deployed in cloud like AWS?

Please let me know, Thanks in advance. Senthil. Mail: senthilkumar369@gmail.com