To change the prices of a single product go to the Products section and select the product.
If the product has a single size (sunglasses, wallets, etc.) you can change the price from the "General" section.
If the product has more sizes (Shoes, Clothing, etc.) you can change the price from the "Variations" section by selecting the different sizes or by setting a single price for all sizes.
To change the prices of multiple products at the same time (if the product has a single size) go to the Products section and select the products by checking the left of the products.
After selecting them from the "Bulk Actions" menu, select "Edit" and click "Apply".
In the new screen you can enter the changes to be made on the products and save them.
To change the prices of multiple products at the same time (if the products have different sizes) it is necessary to download a plugin from those available for Woocommerce.