Dart flights are essential because they stabilize the dart's trajectory and provide the necessary balance for precise throwing. They increase air resistance at the end of the dart, preventing fluttering or drifting.
For beginners, so-called standard flights are best suited because their relatively large surface area provides the most stabilizing effect and compensates for errors in throwing technique. With increasing experience, you can then switch to smaller or differently shaped flights.
Regardless, you can always experiment with other flight shapes. It hardly costs anything. But as mentioned above, we recommend standard flights initially.