How to display Form Fields in multiple columns.
Go to Components -> Contact Enhanced -> Form Fields.
1. Edit each Custom Field and under the General Parameters tab set the Width type to either Bootstrap OR Percentage.
2. Adjust the Field's Container Width to the desired number of columns.
You have to perform steps 1 and 2 for each custom field.
Keep in mind that the field order will be from left to right (top->bottom), so you can have multiple columns. Please see screenshot below for example.
You might also create a CSS Custom Field and add the CSS rule below to make the fields take the full width;