While creating a new product, you can write in the product’s name and descriptions, add unlimited images (based on your package capacity), set the price and weight (this will affect the weight-based shipping rate), and set the initial stock you have of the product (the default stock or if you leave this field blank, it will be displayed as infinite number). For add the images, you can simply drag some photos and drop it.
You may put some keyword tags as semi-filter your customer can find in your website store, and assign which category it belongs to. Learn how to add new category here.
You can also add options and variants to the product. (i.e. this product is available in different colors/sizes). Learn how to create product options here.