Supplements are just that- supplements. You CAN use them but don't NEED to. In fact, I believe that you should start out simple, with your base and micro ferts, and only add supps when you gain confidence and know that your plants are healthy. The exception is CalMAg Plus, and if you find that the EC of your tap water starts out VERY low, or if you are running distilled/RO/rain water, you MUST use it.
Practice using your pH test kit and the up/down to adjust a 'dummy' solution of tap water to 6.0. You'll be doing that frequently.