How to create a website one can upload files to?

Hello.

My first question I have to put in a thread here, and that is how it goes:

My brother is making audio recordings (interviews and concert recordings) and looking for a system to share edited results with.
He will create .mp3 files (or .wav files if necessary) and wants them to share with other people via a UI, like a website and such. A friend of his, who creates webpages for a living, proposed to use the blog format, but since most blogs are linear, especially the free ones, searching for content might be a bit rough and there is no real good overview about the content.

I attached three raw drawings on how it should be:

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I also thought about using Dropbox (Public Link) or FTP, but it might be too complicated for less tech-savvy people.

So my question is, does a system like this exist (probably yes and yes again) and how is it called and how much does it cost and is it easy to implement and maintain?
I couldn't find much information about it, but probably due to my lack of terminology.

Thanks in advance for any help.