@alisamtia Twenty Twenty-Four is a block theme, so it operates differently from classic themes. The homepage is something you build, not something you set. For example, if you want to include blog posts, you add the blocks for that.
To build up knowledge on block themes and the new Site Editor, I recommend reading https://www.ads-software.com/documentation/article/site-editor/ and here’s a full video tutorial if you prefer that:?https://learn.www.ads-software.com/tutorial/intro-to-the-site-editor-and-template-editor/
@nas9286 Similarly, you don’t set a desired page as your homepage, you customize the homepage as desired in the Site Editor. In addition to the Site Editor documentation and video tutorial mentioned above, Twenty Twenty-Four has its own documentation at https://www.ads-software.com/documentation/article/twenty-twenty-four/ and video tutorial at https://learn.www.ads-software.com/tutorial/introducing-the-twenty-twenty-four-theme/
If you need more support with the theme, I recommend asking at https://www.ads-software.com/support/theme/twentytwentyfour/ so the theme’s designers and support community can help you that.