I think you can only do them above and below, not side to side. This blog might help with repositioning of fields if you're skilled in coding:
You can arrange the fields into columns if you like. To do this, just click and drag the field to where you would like it while in the field details portion of the editor:
This can be achieved using Custom Coding. If you have a web dev guy who knows JS, the whole thing should not take more than 1-2 hours. If not, we can help you with this.
Thank you Sanford you have helped me achieve my goal. That's what I was looking for
Moving fieldsets or creating columns would be a great addition to future marketo versions.
Thank you everyone for your help!