It’s not difficult..:D
I cannot work out how to make a new category…everything just appears under ONE category..
I cant work out how I made a sub forum, and when I look in the ACP it isn't there…..
The option to make a new category and then add forums…as has been done here is a mystery…what am I missing?
I also cant work out the correct img link for smileys.. everything I add doesn't work… we need a more detailed HELP section please…one that is idiot proof for users like me.. 
Yes I do think this is a little bit confusing and it is definitely on my list to improve the UX here.
In Forum spark, there is no distinction between creating a category and creating a forum (or sub forum for that matter). A category is simply a forum that has posting disabled.
The very first field on the forum create or edit form is the "parent". That dictates where the forum should live.
A forum with no parent is a top-level forum (or really a category). Every other forum should set the parent field to another forum so it can be placed in the tree.
I think this field is easy to miss though. I'm on my mobile right now but will make a video this afternoon to demonstrate.
As for emoticons, you should just be able to paste in an image URL (eg. https://files.forumspark.net/boards/53f8bd6c-e7b6-4306-8ae1-38154a3c6175/IncF6TO7wZgYOUwkFuCaWnoCA1ZSstMsbURinHus.png). You can use the file manager to upload the images there and then copy the URL over. I need to refresh my memory of this as I've not looked at this section for quite some time.
Edit:
Here's a little video on setting up the forum structure :)
Oooh! that is so helpful. Thank you. 
ForumSpark Support