How to create an application for content generation?

So, I want to create and application that will help me with content generation. So, here is what I want to do.

I want to have some kind of database that will contain all of the articles. Database should create seperate blocks, and every block will have a lot of sentences inside. Format should look like this:

block1:

a1

a2

a3

a4

block2:

b1

b2

b3

b4

...and so on. There would be a lot of blocks and way more sentences in each block (a1, a2, b1, b2, etc. are sentences)

What I want to do is to create an application that will take random sentence from each block (just 1 sentence from each block) and create 1 article from it. It should have a button "Generate" and when I click that button, I would want it to create an article.

Examples of articles:

a1. b1. etc

a3. b2. etc

How should I create it? Can someone help me and suggest what should I use to create that kind of application?

Thank you all in advance