You can easily edit the Header area using the Elementor builder:
Locate the Header link under "Edit with Elementor" menu in the toolbar:
Now you can edit/remove/add new elements of the Header template.
Use the "Navigator" feature to reorder the header elements: https://docs.elementor.com/article/378-navigator; https://docs.elementor.com/article/423-how-to-move-sections-in-elementor
Hit the "Update" button to save changes. Click the toggle button in the left top corner to locate the preview options:
Here you can view the page or exit to the dashboard:
You can also check these articles: https://docs.elementor.com/article/335-create-headers-using-elementors-theme-builder, https://docs.elementor.com/article/459-how-to-create-a-sticky-header
You can also check this guide: Vamtam Elementor Themes: How to make the sticky header to appear on downwards scroll?
Editing the header for mobile resolution
Switch between Desktop, Mobile or Tablet views by clicking on the corresponding icons on the bottom of the panel and edit the content dedicated to the corresponding resolution:
You can also check this instruction: https://elementor.com/help/mobile-editing/