Info for seo

Good morning everyone, my client chose this template because it is very simple, slim and nice to look at. It is currently in progress, so you do not see it online. I noticed that once the site template is loaded it does not have a dedicated page for the homepage, it certainly makes me change the first page, but how can I best index the site since a page is missing? Normally I use the rank math seo plugins.
Thanks and everyone for the answers you will give me

The page I need help with: [log in to see the link]