How to do this (in the description) in Unity2D?

Question

C++ / C#

Hello!
Many times I asked this question here and on Google, I tried to watch it in other games and on YouTube, but there was always something ... not right.
How to do:
1. Link to the button - right? Button bt = new Button; and why it doesn't work
2. How to show+automatic/not, for example, the game menu? On the background of the picture, in front of the button. GameObject Name; ?
3. How to write variables from the input field and where to write them?
I'm just starting to learn, but everything is not working out very well.
Thank you.

Answer 1

Take a course at site, and all questions will disappear.