Easiest is to navigate the categories on left side. Items related to each other are grouped together. In most cases one or more filters on the left will make it convenient to quickly filer a list of products. For example, with filament, you can set a filter for 1.75mm filament.
If you know the products GTIN/EAN of SKU you can search directly on that in the search bar. When entering a part of a product name in the search bar, after a second a list of categories and products matching the search keywords will appear. By pressing the search button, all products that match the query will be shown.