These are some ways you can troubleshoot this issue:
There are no active products
If you already have products on your shop or may have recently set products inactive, check that they've been toggled to Active on the Products page.
The active products are not in any existing category
If you've set up Categories for your products, be sure that all Active products belong to at least one Category.
Empty Categories are not shown on your shop, even if all products are set to Active.
All dates are blocked on the Calendar dashboard
If you've enabled the Calendar for your shop, be sure to check that you haven't blocked any dates.
The available dates for the shop were not properly set
Similar to above, check to make sure you've set up the correct dates for your availability.