How and what can be written in react?

Question

React

Hello colleagues.
Lately I've been sitting and learning react. as if I already began to understand the basics, but in practice I can’t write anything worthwhile for the portfolio yet, how you build the architecture of the react application, what can be done on it. It’s just that I don’t quite understand the concept of redux, redux saga and all that, I would like to get an explanation for this, too, why this is needed at all, they weren’t banned in Google, I would like to get an explanation in simple language and the following additional questions.
1) We made any psd layout and compiled it into jsx and inserted it into the render area or just made it right into the jsx site, do I understand correctly that you first need to make up the project, then divide it through components and whether it is necessary to divide it at all, does anyone have similar examples, +100 to karma))
2) After we have laid out what opportunities react will give me, it would be better if we described some of its capabilities and where you can find all the examples, I'm not talking about off-documentation, but what can be done on it.
3) What application can be written for a portfolio in order to at least have an understanding at the initial level for a junior position.

Answer 1

- hello, police?
- yes...
- I'm sitting and learning React, others have been using Vue, Angular for a long time or manage JQuery with html, , I'm waiting for explanations in simple language...
- I understood everything, try to speak calmly and answer only "yes" or "no". Are you being threatened with a gun?