I just need to verify as I prep for my second game. There is no specific order of operations? You can move then shoot or shoo t then move correct?

More specifically, could snowtroopers, aim, move then take their free attack?

You can perform actions in any order, with the exception of actions that are the result of a triggering event. Your example of snowtroopers doing an Aim action, then a Move which triggers an attack action is correct.

They could not Move first, then interrupt to Aim before attacking.

Yes, there is no mandatory* order of actions, but usually you will want to aim first, shoot second, for example

* But there are situations where the timing is important. In the case you just said, Snowtroopers can perform the free attack AT THE MOMENT when they finish the movement. For example, you can NOT say "I first move, I check that I'm in range, now I aim, and now I make the attack that the first move gave me".

There is also other situations where the timing is also important, like when you use Compel or Dauntless.

Good to know. Different from what I am used to but good.