Element that allows you to post item to sell (Post your ads)

Hi fellow people in Sitepoint.
I need guidance on how to make an element in my website that allows users to post their ads item to sell and it will update automatically when a user made their add and post it on the website.
good example is like this:

and when u click one of the item, it will link you to another page that shows a content of the item description and seller contact details that looks a bit like this:

Correct me if I’m wrong (which likely to be):
Are these elements, blog integrated?
If not or yes, what is it and where can I find a good tutorial or books that will give me some guidelines.

Thanks :slight_smile: