Travel hacking is just a fancy term that entails using existing systems to your advantage to get discounted and free airfare, hotels, car rentals, and other travel expenses. So you can get your next vacation on the house!
You can get started on steps 1-4 today pretty easily, and then steps 5-6 are ongoing steps that you will use over and over again as you get more familiar with travel hacking.
Every credit card will have its advantages, but there is no doubt that some are better than others. Especially when you consider all of the perks that credit cards could offer.