Routing Error uninitialized constant SubmitsController (Trying to upload document using Carrierwave) - ruby-on-rails

Question

I am building my first useful Rails application for a teacher to post assignments and students to upload their work (jpeg|pdf) on the website using Carrierwave.
Tutorial I want to replicate: http://www.tutorialspoint.com/ruby-on-rails/rails-file-uploading.htm
Error: "`undefined method submits_path' for #<#:0x007f7260dbc7a0> Did you mean? submit_path"
Error message: Extracted source (around line #14):
13 <div class = "well">
14 <%= form_for #submits, html: { multipart: true } do |f| %>
15 <%= f.label :name %>
16 <%= f.text_field :name %>
17 <%= f.label :attachment %>
model: submit.rb
class Submit < ActiveRecord::Base
mount_uploader :attachment, AttachmentUploader # Tells rails to use this uploader for this model.
validates :name, presence: true # Make sure the owner's name is present.
end
controller: submit_controller.rb
class SubmitController < ApplicationController
def index
#submits = Submit.all
end
def new
#submit = Submit.new
end
def create
#submit = Submit.new(submit_params)
if #submit.save
redirect_to submits_path, notice: "The assignment #{#submit.name} has been uploaded."
else
render "new"
end
end
def destroy
#submit = Submit.find(params[:id])
#submit.destroy
redirect_to submits_path, notice: "The assignment #{#submit.name} has been deleted."
end
private
def submit_params
params.require(:submit).permit(:name, :attachment)
end
end
routes:
Rails.application.routes.draw do
resources :submit, only: [:index, :new, :create, :destroy]
get 'welcome/index'
get 'welcome/about'
root 'welcome#index'
end
schema:
ActiveRecord::Schema.define(version: 20160903040246) do
create_table "submits", force: :cascade do |t|
t.string "name"
t.string "attachment"
t.datetime "created_at", null: false
t.datetime "updated_at", null: false
end
end
rake routes :
Prefix Verb URI Pattern Controller#Action
submit_index GET /submit(.:format) submit#index
POST /submit(.:format) submit#create
new_submit GET /submit/new(.:format) submit#new
submit DELETE /submit/:id(.:format) submit#destroy
welcome_index GET /welcome/index(.:format) welcome#index
welcome_about GET /welcome/about(.:format) welcome#about
root GET / welcome#index
Thanks in advance to all the wonderful people here who are willing to lend a helping hand

Answer 1

You're using #submits insted of #submit, here:
<%= form_for #submits, html: { multipart: true } do |f| %>
Shoul be:
<%= form_for #submit, html: { multipart: true } do |f| %>
Which is the variable you have created in the controller, here:
def new
#submit = Submit.new
end
EDITED ANSWER
I'm gonna take a step back here and point some problems you're facing due to Rails Convention.
The Rails philosophy is Convention Over Configuration. That means that if you follow some conventions, Rails will be able to do what you expect it to do it without configuring anything (or almost anything).
Besides the error I pointed above, all the other errors you have listed in the answers are because you created your controller in the singular SubmitController instead of SubmitsController. This changes the convention expected by Rails, so you would have to some configurations by hand.
Since you're following a tutorial or something, my advice is to take a step back and re-create your controller with the right conventions.