Ok let’s start with the categories first.
The first thing that you have to do is to create the categories that your directory will have. In order to do that, go Directory -> Listing Categories
There add all of the categories that you want without any particular order it won’t matter.
Let’s assume in your case that your directory will have those categories:
Agriculture – import-export
Bedding plants, bulbs and seeds
Beekeeping and silk culture
Beer
Biscuits
Champagne and sparkling wines
Oils and fats, edible
Electricity – import-export
Electricity and distribution
Abrasives, mechanical
Aluminium and aluminium alloys
Agricultural systems and equipment
Agriculture and forestry – machiney
Aeronautical equipment manufacturers
Pleasure boats
Anti-corrosion products, chemical
Biotechnologies
Asbestos-replacement products
Foams, rubber and plastic
After you create them, go to Appearance -> Menu
There you’ll create sections – menus for the categories that you want to group. Let’s say that you want a section that is called Agriculture and Livestock. You’ll create a menu with that name and then on the left side of the menu tab you’ll drag the Listing Categories that you want. After you do that, you’ll simply hit Save menu again.
After you create all the sections, you can go to Pages -> Add New
There you’ll create one new page and you’ll name it Home and one more where you’ll call it Blog.
You’ll open Home page again and on the right side, you’ll see an option where is says Template. Click on that and choose the Default Template to Directory. After you do that, click the update button.
After you do that, go to Settings->Reading and where it says Front Page Displays click on Static Page(Select Below) and choose for Front page the Home page that you created earlier and for Posts page, choose the Blog page. After you do that, click save.
Then go to Appearance->Widgets
There you’ll see various widget positions. The directory1, directory2, directory3, directory4 etc positions are where the menu sections should be placed. In order to do that, drag tha custom menu widget to the position that you want, select from the drop down menu the section that you created earlier and write again the name of your section where it says title. Hit the save button and repeat the process for the other sections as well.
Once you do that, go to the front page and you’ll see that your categories appear there.