We have 3 types of the store blocks that you can use:
1. Category list — a block with tabs to display several categories.
2. Products — a block to show selected products (even from different categories).
3. Storefront — a block to display a single category.
To add any of these blocks, click on the “plus” icon in the editor:
Then navigate to the Store section:
You'll see 3 blocks there, and below we'll tackle each of them.
The category list block allows you to display several categories in a convenient way.

1. To select a category for each tab, click on the gear icon:

The products block lets you choose particular products from your store and display them in a collection. Basically, in this block you can select products from various categories and change them manually if needed.
1. To add a product, open the card settings by clicking on the "gear" at the top left corner:

Storefront block lets you display a single store category on your live site. Even if you add/ delete products in the store settings, the catalog in the storefront will be updated automatically to reflect all the recent changes.
1. To choose a category, hover over the block and access its settings: