Should Figures and Tables follow a certain order or be at a specific location in a document?
There are many policies that publishers imply considering figures. The most common ones are:


All figures or tables (so-called floats) have to be numbered and get a caption.
All floats have to be placed at the top of the page, or at a page solely made of figures and tables.
All floats have to be referred in the text by their number.
Every float has to appear no sooner than on the page where it is first mentioned (i.e. if it's first mentioned on page 5, it shouldn't be placed on page 4, but it can be placed on page 6).
Numbering should be consecutive (i.e., no 1 then 3 then 2).
The first reference to the floats should be consecutive (with the exception where you basically only "confer it" (with "cf." or alike).


Some journals want you to provide figures and tables separately, some don't care, some have typesetters that do it themselves, some don't force captions, some allow in-text placement, etc. Just check what you have to do. If nothing is said, I recommend complying with the rules above.