Since you already ordered something, this may not matter, but something lighter tends to be more controllable and longer handles tend to be safer, at least getting away from hatchets and pack axes (20" and under handles).
The short handles require a little extra safety measure since missing the target can more easily have the head coming back at you, where as a lomger handle puts it in the dirt, or at least gives you more time to stop it. It's also just generally better that the work is happening further away from you in the case of somwthing like a 14" hatchet and 24" boy's axe or hudson bay axe.
Looks like the Helko Werk scout axe should be a fine starting tool with a little safety training to go with it, if they haven't already.