How do I start a new thread/topic? I’d start a new one to ask that, I really would, honest, but . . .
When you’re in each forum/category, there’s a button at the top of the page that says “+New Topic.” In the theme I’m using it’s in the top right.
Nothing like that. A + next to a bell opens a form for “optional tags” with a search field and a “Type here” field. Search field returns “not found”.At the botton is a “Create topic” button. but nothing happens if I click it.
Try typing the text of your post in the ‘type here’ field. That’s what it’s for. 
And type the title where it says ‘type title’.
Then click ‘Create topic’. It won’t post an empty topic if you leave the text blank.
I Filled in text where it says “Type here”. What do I do then to make the “type title” field apprar, and where should I be looking for it?
It sounds like you’re trying to fill in the area where you add tags or search for tags. You don’t want that, you want to start a topic.
But that is the only field that open when I click [+] at the upper right, where “new topic” is supposed to be, but isn’t. For those of a normal display, how do you open “add tags”, if the “plus” button opens “new topic”?
I can only guess that you are using a phone with a small screen, and that part of the form isn’t visible.
It should look like this (I reduced the size of my screen to make it clearer):
I’ve solved the issue. See “bizarro zoom” thread.