How would I go about animating non player objects like this?

I would like to animate a model with various parts, a weapon, I don't really think I want to do something as tedious as modifying the cframe over time in code, as it may look even choppier than how an animation from the animation editor from me, but I am not sure how to approach that, because it only seems to work with the rig builder option.

I know you need a HumainoidRootPart, but it also noted it needed to be hooked together with Motor6d s but, I see no reason for them and I actually have no clue on how I would add those either, unless though code, and again, I'm not sure if that would save properly, etc

It will not let me select the HumainoidRootPart in Roblox's animation editor, but I'm not sure.

Mind leading me in the right direction?

Here is my object:

3D View: https://i.imgur.com/NQPll0j.png

Workspace: https://i.imgur.com/YAimheW.png

There is no highlighty box for my weapon when I open the animation editor: https://i.imgur.com/82V4oiJ.png

Unlike a newly made character rig: https://i.imgur.com/HYKi9Ra.png

It says that it needs to be about scripting, but I'm not sure if this is in a grey area or not because it isn't specifically scripting, although still involving the editor and if I have to script animations, or even an animation system or something along those lines. Thanks in advance!

I hope this is enough information and if you need any more, please let me know, thanks :)