To begin with your site will probably look something like this
The first setup is to set the homepage in the customiser which you can find in the toolbar along the top of the screen after logging in as an admin.
In the customiser, navigate to "Homepage Settings"
There are two radio buttons. Make sure "A static page" is selected. Two dropdown menus appear called "Homepage" and "Posts Page". If you don't have pages setup already for these two pages, click "Add new Page" and setup two static pages. Once done click "Publish".
You can then close the Customiser. You will see an empty page with your page title and some widgets. The next step is to apply the Homepage Template. To do this click "Edit Page" in the Wordpress Menu bar.
After clicking "Edit Page" the block editor will load. In the menu in the side, navigate to "Page Atributes" and from the dropdown menu that says "Template", select "Homepage" and click the "Update" button in the top right.
The next thing you need to do is set a Featured Image and add some text (and potentially a button) that will appear in the splash screen on the homepage. N.B. If you don't add a featured image the splash screen with all the sections won't appear.
Click "Update" again and then go View your page! It should look something like this
To complete the homepage setup you can add widgets to the various widget areas and use the customiser to set the "Skills for Life Theme" options and change any Colours.