Start by avoiding the expensive mistakes. The perfect quiver can wait. The biggest mistake beginners make is buying gear before they understand their real wind range, their local spot, their body weight in relation to kite size and the difference between safe beginner equipment and performance gear.
A good first setup should give you more safe water time. It should be easy to control, easy to relaunch and suitable for the conditions you actually ride most often. That usually means one all-round freeride kite, a compatible bar, a comfortable harness, a forgiving twintip board and the protection you need for your local water temperature.
Look for gear that gets you on the water more often and helps you progress faster, even if it is not the most advanced kit in the shop. That is also how you avoid replacing half your setup after three months.