For the scroll to location along with correct active menu item highlighting, perhaps take a look at a video I put together on the subject of a one page web site as you are wanting to achieve. I haven’t tried this with GP with it’s own sticky menu, so you may not need the plugin mentioned that does that part.
And here is a site that I build that uses this method:
I am going to work on trying this method with GP and Elementor and will post back when I get it working 🙂
Tutorials and tips for GeneratePress, WP Show Posts, WordPress and Elementor