How to automatically load configuration files at emacs startup

(load(expand-file-name"~/.emacs.d/init"))
;; Scroll line by line
(setq scroll-step1)

<Packages
;;; package.el
(require'package)
;; Added MELPA
(add-to-list 'package-archives' ("melpa". "https://melpa.org/packages/"))
;; Added MELPA-stable
(add-to-list 'package-archives' ("melpa-stable". "https://stable.melpa.org/packages/"))
;; Added Marmalade
(add-to-list 'package-archives' ("marmalade". "https://marmalade-repo.org/packages/"))
;; Add Org
(add-to-list 'package-archives' ("org". "http://orgmode.org/elpa/"))
;; initialization
(package-initialize)

;;mozc
(require'mozc);loading mozc
(set-language-environment "Japanese"); language environment to "Japanese"
( setq default-input-method "Japanese-mozc"; IME to Japanese-mozc
( prefer-coding-system'utf-8); default character code to UTF-8

;; C++ indent
(add-hook 'c++-mode-hook' (lambda() (c-set-style "ellemtel")))
(add-hook 'php-mode-hook' (lambda() (c-set-style "ellemtel")))

;; Do not display Emacs menu screen at startup
(setq inhibit-startup-message t)

;; Do not display messages at startup
(setq initial-scratch-message"")

/////////////////////////////////////////////////
;; Invalid indentation at line feed
(electric-indent-mode-1)
////////////////////////////////////////////////

;; Comment color to green
(set-face-foreground'font-lock-comment-face "green")
  
(global-font-lock-mode); character coloring

(custom-set-variables
 ;; custom-set-variables was added by Custom.
 ;; If you edit it by hand, you could message it up, so be careful.
 ;; Your init file should contain only one such instance.
 ;; If there is more than one, they won't work right.
 '(ansi-color-faces-vector)
   default default underline success warning error)
 '(ansi-color-names-vector)
   ["#2e3436" "#a40000" "#4e9a06" "#c4a000" "#204a87" "#5c3566" "#729fcf" "#eeeeec"]]
 '(package-selected-packages)
   (quote
    (auto-complete dash mozc popup mozc-im mozc-popup mozc-temp ac-mozc)))
(custom-set-faces
 ;; custom-set-faces was added by Custom.
 ;; If you edit it by hand, you could message it up, so be careful.
 ;; Your init file should contain only one such instance.
 ;; If there is more than one, they won't work right.
 '(font-lock-function-name-face((t(:foreground "orange4"))))))
 '(font-lock-type-face((t(:foreground "blue"))))))
 '(mouth-drag-and-drop-region((t(:background "cyan"))))))))