No real revelations here and seems obvious but....don't forget to add primers before filling with powder.lol That one has bit me a couple times.
If you can swing it, buy better equipment at the start vs. dipping your toe in the water with cheap gear and then inevitably getting better quality stuff down the road and spending much more than you otherwise would have.
Something I wish I would have told myself when starting out - pick a bullet you want to shoot and stick with that one bullet and build loads around that vs. getting several boxes of different bullets, weights, powders, primers and then drive yourself crazy trying to work up a million different loads. Pick one or two and limit the variables.