How can I tween a model 10 studs to the left?
Use its PrimaryPart. But you need to weld all the other part to the PrimaryPart for this to work tho.
If you’re looking to smoothly animate the model, the easiest technique I’ve found for this is to assign a root part (primary part) of the model, weld everything to that primary part and unanchor them, then tween the primary root part of the model using TweenService. The other parts will follow it.
There is no definitive answer to this question since it depends on the specifics of your model and what you are trying to achieve. However, one approach you could take is to use the ‘Insert keyframe’ button in the timeline and then manually move your model 10 studs to the left.