For my forum. I want each Category to have updating icons.

For example, I want the icon to update when there is a new post in a forum within the category

And I want the forum icon to update everytime there is a new post in that thread.

You can change your category/forum icons with whatever you want here: Admin Panel > Display > Pics Management > Advanced mode > Icons for the forum.

Yes, I can but they do not have a changing function, no matter what I try the image stays the same, I want it to change if there's a new post within the category/forum but right now they all remain static.

You do understand that new posts/topics by you will not appear new to you.