If you mean Kentico Biz Forms on the front end, then what you can do is go to the Form tab and select the 'Use custom form layout'. Here you can either 'Generate table layout' or create your own using Divs or whatever HTML you want using the Source option from CK Editor.
Then you can add in the class/id and using CSS you can then align the form labels and fields.
I would recommend that you 'Generate table layout' then go to the Source code of it and add the HTML you require around the fields.
Hope this helps
Ilesh Mistry from MMT Digital's K-Team
Certified Kentico Developer