It's me again. Sorry. It turns out before the fields and category update, the time were whenever I made a field it would bring to a error page, well it turns out all those times I tried to make a field actually worked, but just did not appear, and now I have multiple of the same fields. Sorry!!!
It depends whether you’re talking about categories (the different tabs) or fields (the subheadings under each tab). To delete a field is very easy from the page settings screen: just click on the field and there will be a ‘delete this field’ button. To delete a category is tricky at the moment especially if it has no fields in it, and andrew (Our Supreme Lord and Overseer)’s working on making that better, but a workaround for now is to
add a field to a category you want to delete,
delete that field
If you do that for every field in a category, it should delete the category.
(With screenshots if that's a better help:)