There are a bunch of free sites for creating svgs of boxes and you can use any of them.  I made a box 2 inches in each dimension, 3mm thickness of material, with finger joints and then adjusted the spacing of the joints for something that fit the box size nicely.

Create a boxy question mark (you can trace it from an image with the Vector Edit tool if you prefer), mine is about 27mm high  Create 6 circles each around 5mm.

Make copies of each.  You'll need 24 circles, 4 for each side and 5 question marks (you can't see the bottom so I didn't put one there)

To make gluing easier later it helps to make a template for the glue up.  I created a box at 50.8mm square and set that to Score.  I put 4 circles and the question mark in the placements that I would want them, selected all 5 and choose Combine.  I added 4 circles, one to each corner, so that I would be able to see the edges of the box through the template.  Select everything but the box and set it to cut.  The box should be score (to aid with alignment and centering).

Assemble your box.  I suggest test fitting everything before adding glue so you can be sure which pieces go in which order.

After the box is glued you can add your pieces.  Align the template on top of the side of the box using the scored lines as a guide.  Add glue to each spot and drop in the corresponding piece.  Don't add too much glue or it will squeeze out and glue your template down with it.  Work around the cube until you have all 5 sides complete.

Enjoy your cute litte decoration!