The first step to creating a map layout in ArcGIS Pro is to insert a new layout into your project.
When you create a new map layout, it will first display as a blank piece of paper. You will need to add your map(s), legend, and other map elements to the layout.
You can activate a map frame if you need to adjust the scale (e.g. zoom level) or placement of items within that individual frame. Activating the map frame will let you zoom in/out on your map, change the view of your maps, etc.
Adding snapping guides to your map layout will help you save time when you're trying to align your map frame, inset map, and other map layout items. You can add multiple horizontal and vertical guides to your layout to help you place layout items at your preferred locations.
You can use the Graphics and Text features in ArcGIS Pro to add a title to your map:
After you add a layout element (e.g., scale bar, north arrow, etc.) to your map layout, you can use the menu bar (or right-click) the item to further customize its properties.