In Studio, boxes are stacked on top of each other. To place boxes horizontally, select the parent box and change the stacking direction to horizontal.
Steps
Place the parent box.
Place the elements you want to line up in a parent box.
Select the parent box and set the direction to ← or →.
The boxes line up in the direction of the arrow.
If this does not work, please contact support via chat by clicking on the ? at the bottom right of the editor/dashboard and contact support via chat.