No need to be sorry. You will get as much help as can be provided with the information you give.
That's fine the site isn't live but can you direct us to a link of the page you want the icon to appear on? If you don't want to show us a link of your site, give us a link from the demo site.
.tpl code is the template file you want edit. Code is what the file contains. If you know what template you want to edit and you post the code, I or someone else would be happy to show you what to add.
You're right we don't need your graphic but based on the lack of other information I asked to get an idea of where it might be. Now my crystal ball is cracked.
It would be great if you could add your complete version number to your forum signature as per the forum rules, because from version to version there are slight differences. It is relevant. You can add it by editing your forum profile.
Category icons work like this generally.
If you click on a category and it has subcategories in the customer front end, you will see a list of sucategories in the central area of your store and the category icon will be displayed as well.
If you click through one of these "first level" subcategories and there is subcategories under that then you will see the first level icon as well as a list of the subcategories under that one.
See how confusing this is?
Category
Category>Subcategory1, Subcategory2 (shows Category Icon)
Category>Subcategory1>Sub-subcategory1, Sub-subcategory2 (shows Subcategory icon)
Maybe this link will help you. Remember to backup before trying anything and please take the time to read through the Forum Rules (in the Forum FAQ area), they will help you get around here.
http://forum.x-cart.com/viewtopic.php?t=8677