To import your Product catalog, you need to respect a certain order. If your product catalog refers to categories and manufacturers, these elements must already have been imported.
Start by logging into your administration area. Then access the list of categories by clicking on the "Catalog" tab, then on "Categories", in the column on the left of the page.
In the top right of the categories list, click on the "Import" icon to open a page where you can define the various parameters for the categories before importing them.
You must choose a file in CSV format for importing your categories. Please note that there are sample CSV files to download on the same page.