Hi! First of all I just want to inform you that I don't represent OvicSoft in any way. I'm just a customer just like you.
If I understand the problem correctly, you have to add the categories manually to the menu. I'm assuming you're talking about product categories.
I also assume that you have choosen a menu to be placed on the left side of the home page. Open the admin panel, and go to Appearance > Menus. Choose the menu you want to edit (in this case the menu with the categories), and press "Select".
You can now add and remove categories. To the left side you will find Pages, Posts, Custom Links, Categories and Product Categories. Choose the last one. Here you will find all your categories. Now you just have to choose the categories you want to add, and press "Save Menu".
If you can't find "Product Categories" on the left side, take a look at the top (you have to scroll up as far as you can). Here you will find "Screen Options". Press that, and tick off "Products Categories". You might have to reload the page after you have done this. You can now see "Product Categories" on the left side, and you are now able to add product categories to your menu!
I really hope this help! If not, please let me know :-)