No, there is no other way, you can do that through CSS only. You can make use of the bootstrap components and create a good UI. For the two columns, you need to make use of the section field.
Make sure you have bootstrap CSS in the head section.
1) In the form settings [for the form] – provide the CSS class: row
2) Add Section – In the section CSS Class property enter - form-group col-sm-6 col-xs-12
3) Add Form Field in the Section that you added. For example: Single-line text and provide the CSS class: form-control
4) Similarly, for another field, repeat step 2 and 3
I've followed the steps defined here responsive Sitecore 9 form bootstrap -- This will help you in setting up a form with fields side by side. Please refer the gif carefully, where it shows, how to add the proper class for fields and field sections.