Drawing and sheathing weapons

[DeShurland]

I picked up a Halberd last night & normally use a greataxe.

In combat i would want to do the following; I attack using the halberd/take advantage of its reaction and opp attacks. How does that impact with sheathing it, then pulling out a greataxe to attack and move closer? Is it generally a bad idea? Am I simply dropping the halberd and then picking it back up afterwards?

I am a level 5 fighter battlemaster (Distraction, precision and trip), so would it take my extra action action?

Just debating about acquiring something a bit less cumbersome, so i can sheathe the halberd (although I have no idea how you even begin to sheathe a halberd) and then pull out a one handed shortsword when something gets closer etc.

Thanks

[hymer]

You get one free item interaction per round. I'm not sure you can actually 'sheathe'* a halberd - you'll have to ask your DM. But suppose you can, you can use your free item interaction in your turn to do that. But then you don't have a weapon to hand any more.
You are free to drop the halberd (costing no action), and use instead your free item interaction to draw your axe.

Any item interaction beyond the free one once per round, you would have to spend your action.

You do not get an extra action as fighter. You get Action Surge (which is a precious and limited resource), yes. And you get Extra Attack, which allows you to attack twice with one action - not two actions that you can do what you want with. This is an important distinction.

*Edit: A note on the sheathing of polearms (https://youtu.be/YpUcsIwW0kQ?t=171). He is little longwinded, but makes the point that you pretty much have to carry your polearm in your hands.