If you have 20 products, you have 20 things. In Drupal-speak, you have 20 entities.
In Drupal, every "thing" is an entity-- pages (nodes) are entities, and comments are also entities.
Each "thing" should be its own entity type. Drupal provides a lot of tools for linking different entities (such as Entity Reference module) and displaying entities (such as Layout Builder module and Views module). But, all of these tools assume that each "entity" is representing a single thing.
So, if you put 20 products in one entity (node/page), you will prevent yourself from using most of Drupal's features that make it a great CMS.
Instead, I suggest making a custom content type, Product. You can add just three fields to the product:
Next, create 20 products by adding content of your new content type Product.
Then, create a view using the Views module. This will give you great control over how the products are displayed-- you can make a simple list of products to start, and if you want to expand it later, you can show related products and do many other cool things.