There are several to options to choose. You can change navbar style and scroll effect globally via Appearance > Customize > Main Navbar  > Main Navbar

Navigation:

• Navbar Style – choose between normal and narrow style,
• Navbar behavior – choose how the navigation bar will act after scrolling the page:
  – Scroll Up Menu
  – Scroll Up Top Bar
  – Scroll Up Both
  – Fixed Top Bar
  – Fixed Menu
  – Fixed Both
• Navbar transparent,
• Search on navbar,
• Navbar search label – set custom text for search label,
• Navbar search icon class – choose FontAwesome icon for the search label