Yes, you would need to make a relatively substantial power supply. You would need to find something around a 48V, center tapped transformer good for at least 5A or 100+ watts. And a power bridge rectifier and some big filter capacitors.
No offense, but the questions you are asking would lead us to believe that you may not be ready for such an advanced circuit construction from scratch. You may be better advised to get a ready-made amplifier module like the ones available from Apex Jr.