You may check mendix Docs : https://docs.mendix.com/howto/front-end/atlas-ui/
Some nice Academy learn paths like :
But for easy start point:
with Mendix Studio – you can change branding color and themes
with Mendix Studio Pro – you can create new Layouts and reuse in your pages. As well, change your Sass and apply styles in your widgets/containers;
Hi, have a look at the academy learning path:
Right click on the module in studio pro and see the option for creating custom layout. Once created you will be able to select this new layout for your pages.