Cannot load preview-latex despite AUCTEX already installed

Question

I have installed AUCTEX from inside emacs (i.e. M-x list-packages) and according to preview-latex manual, the installation of it is already included when installing AUCTEX. But when I tried to load AUCTEX and preview-latex by adding the following lines:

(load "auctex.el" nil t t)
(load "preview-latex.el" nil t t)

into my init.el file, it cannot load preview latex saying that.

File is missing: Cannot open load file, No such file or directory, preview-latex.el  

Moreover, quoting AUCTEX manual

You can detect the successful activation of AUCTEX and preview-latex in the menus after loading a LaTEX file likepreview/circ.tex: AUCTEX then gives you a ‘Command’ menu, and preview-latex gives you a ‘Preview’ menu.

but where do I find these 'menus'?

EDIT: Another part of the manual says that

With Emacs (or if you explicitly disabled use of the package system), the startup files auctex.el and preview-latex.el may already be in a directory of the site-start.d/ variety if your Emacs installation provides it.

The file auctex.el is in the .emacs.d/elpa/auctex-12.1.1/ where I expect to find preview-latex.el but I don't. There do exist preview-latex.info and preview-latex.spec in that directory but the file preview-latex.el is found in another path .emacs.d/elpa/auctex-12.1.1/tests/japanese/ (I bought my laptop in Japan in case that matters).

I am using GNU Emacs 26.

Answer 1

With ELPA-installed AUCTEX you must not do

(load "auctex.el" nil t t)
(load "preview-latex.el" nil t t)

Just remove those lines and it should be ok.

As per the menus, simply open a latex file, and you will see additional Preview, LaTeX, and Command menus either in the window (frame in Emacs parlance) or on Mac OS X for some Emacs builds in the top menu bar.