What do you need to know to write a questionnaire program?

Question

Programming

An idea came up. In order to force myself to study HTML + CSS, and consolidate what I have already learned, I decided to write something like a reference book - a questionnaire. But my knowledge in all PL is not so great.
Familiar with C ++, in the console. But, I would like the program to have a presentable appearance.
Although, this is not the point. Simply, never wrote such projects. Tormented by the question of how to store information?
How is information usually stored in such programs? And how to get it at startup?
Please provide the points necessary for the implementation of this idea.

Answer 1

In files or in the database - respectively, when starting, we read the file or execute a query to the database.
1. Learn how to make dialogues for a survey - with a sequential output of questions
2. Learn how to take questions with answers from an xml or txt file
3. Learn how to save answers to a csv file as a string
4. Learn how to save to a database