Build me a basic website

I want to make a website, and i am breaking down the tasks in different stages, here is the initial requirement and will post further requirements once the first stage gets complete: Stage 1: A working website with Front page and Sign Up page: i) Main page/Front page with 5 tabs, in which i can add information later from my admin account. The Tabs will remain in place throughout for all users and admin. Front page will have login password fields for existing users on top right corner and a sign up button below it for new users. On clicking sign up the viewer will be directed to the Sign Up Tab. In stage 1 we only require text posting and commenting on main page, in later stages we will give facilities to add photos, videos and google map location also on main page tabs. ii) Last Tab on Main page will be for the Sign up where sign up can be done from Google, Facebook, Twitter, and Instagram. This tab will disappear for logged in users. iii) My admin account from where i can add information on the website which would be visible only from my account, with a button on each page, tab and post to make it visible or invisible to everyone (signed up users and non signed up viewers) . Also i should get notifications about every new user sign up, and approval notification for a new tab creation on the main page of website. Admin should be able to send inbox messages to users. iv) The users after signing up, should be able to add any new tabs that will be visible only to them and a button to finalize it and ask for admin approval and on pressing it a notification should pop in admin account for approval. Users should be able to send inbox messages to [login to view URL] accounts after signing up will be displaying their profile page, and all the tabs and menus of main page will be in same place as on the front page. No permission will be required for their profile updation or any additions in their own profile. No permission will be required for posting/commenting on existing tabs or tabs approved by admin on main page. v) Kindly mention domain name cost and server costs as well NOTE: 1) I require the website code as an open source, the code should be easily viewable and editable from Admin account. 2) Kindly send me quotations for the above 4 tasks of stage 1. Quotation break up for different task components will be appreciated. This will help me to decide whether to keep these components here in stage 1 or to shift any in stage 2.