I want to make my own craigslist style site.
I want it to have category style posting ie: [New Listing] -> select category [Electronics] -> select subcategory [Game Consoles].
I want it to have a jsp style posting system that has a post prefix [ WTB ] or [ WTS ].
I want it to have commenting/replying directly in the post, rather than having to have emails sent back and forth.
I want it to have ONLY facebook/social login.
I need it to be mobile friendly.

I've been through most of the codecademy "Build a website" courses, and that's all fairly simple, but that doesn't really help me understand what coding languages I need to make a site like this, or teach me how to do certain things like having a report posting page and admin panel, etc.
I don't understand things like how to create a working functioning interactive website. I understand how to create simple html webpages and using css styles to theme it, but to have logins and input fields to make posts and whatnot is beyond my level of comprehension.

Where do I start?

This post was edited by ThePwnEffect on Dec 15 2014 06:35pm

if you intend to make $$ from this site, i suggest you start by hiring a developer to do it for you.

if you intend to have people other than you using this site, i suggest you start by hiring a developer to do it for you.

if none of the above apply, i suggest you look at a server side language. you have a lot of choices. php, ASP.NET, python, etc. just keep in mind you're in it for the long haul. you'll spend many months on it if you're coding it yourself as a newbie. it will also be extremely difficult to convince people to use your site. you'll likely have to pay people to "use" it while you're marketing it. but if this is just for a hobby or instructional purposes, have fun

Is it really that difficult to do?
My only intended source of revenue is non intrusive ads.

Hiring someone to do something like this would be very costly, would it not?

Is there any software that at the very least (for free or very cheap) has most of what I'm asking?
I've tried OSClass, OpenClassifieds, tried using SMF forums, and it's all very limited.
Only thing I haven't tried is WordPress with a Classifieds theme/addon, due to the high cost of these themes and the lack of being able to really test them out before purchasing.

My family members wouldn't even use my first website.

It was so sad.

LOL

aim lower bro. you are a nub.

general knowledge of: php, sql, javascript, css, html will permit you to accomplish all of the above.

html, css: visual and design aspects, including a mobile friendly interface, keyword: responsive design.
php, sql, javascript: all functional requirements can be met with these. both javascript and php will provide the desired function while sql will provide help you meet data storage/access needs.

as for the fb login, you can use either the php or js sdk. https://developers.facebook.com/docs/

there are many resources on the web, use google to find tutorials which are appropriate for your skill level in the above languages and invest the time.

PHP is not good for the long haul though, it is a declining language as far as backend development goes

facebook disagrees with you, they run php, same with wikipedia. granted many web presences are transitioning away from it and towards java/rails/python platforms (among others). that still doesn't change the fact that its a perfect introductory language for his project.