Question:
How do I add columns within a form?
Product:
Wix Studio
What are you trying to achieve:
Adding columns to a form.
What have you already tried:
Several help articles - nothing found for Wix Studio, only for Wix and EditorX.
Thanks in advance for help 
I had the same question, but I just figured it out. You need to divide your section into sections (columns). Create a section for every column that you need. Then create individual forms for each section. So you will use multiple forms to create one because they will be side by side.
If you aren’t sure what I mean, try to add the “contact us” predesigned form that has 2 columns. You should understand what I mean by looking at that form.
I found an easier way. We can actually drag the width of the boxes in the form. Make the box smaller so that there is space to put another box next to it. Drag the next box to the empty spot.
Just found it a moment ago and then saw your reply. Yes, that was indeed the solution! Thanksies 