Basic bodice, puffed sleeves, full skirt and peter pan collar. Petticoat, pantaloons, and basic pinafore/apron with wide straps.
Simplicity has 8669 view B as a good apron starting point, round the neckline (and you can see what I mean) and 8686, pleated skirt which would look less full on the body.
Here is a real life Alice during the animation showing how the dress should look.
But like everyone says, this is very likely one of the easiest things to make, and not much of a pattern is needed. I can send you a draft of the pinafore if you want it, or how to draft it yourself, same with the pantaloons if you can't find that, or any other part you have issues with. This costume, or a variant thereof, seems to be the go to costume for theater where I am...and the one no one can ever seem to make or find the right pattern for.