Hi there,
2 things:
1. Split displays the Recent Posts on the Home Page. If you want to change this so you can add your own content then:
a. Create a new page.
b. Dashboard > Settings > Reading and change Your homepage displays: Static Post > Your new page.
Now you can edit the page for your own content.
Note – you may want to do the same for creating and assigning your blog page….
2. a Header Element is used to display the hero section with the buttons. You’ll find them in Appearance > Elements:
https://docs.generatepress.com/article/header-element-overview/