Problems encountered during the first use of vim and common methods

Problems and common methods encountered when using vim for the first time abstract: problems encountered when using vim for the first time E353: Nothinginregister I learned from linux and python. vim is the best editing tool in linux, of course, I want to learn more ~~~ First, let's take a look at the problem. I enter it from the terminal... for the first time, I encountered problems and common methods when using vim.
Abstract: The first time I used vim, I encountered the problem E353: Nothing in register. I am a beginner in linux and python. vim is the best editing tool in linux. of course, I have to learn how to compile it ~~~
First, check the problem. I enter vi from the terminal to enter the welcome page of vi,


Then, I am dumb to see the help above, and really want to help vim usage, so I typed: help, the problem occurred:


E353: Nothing in register is displayed in the lower-left corner of the terminal.
This is not a problem, but a wrong operation, at this time, you only need to press [I] or [a] to enter the vi insertion mode and you can edit it...
Finally, I will popularize the basic concepts of several types of vi for linux beginners like me:
Vi working mode:
1. command line mode: Move the cursor back and forth between characters to delete, copy, and move characters. Press [I] or [a] to enter the insert mode, and press 【:] (colon) enters the last line mode
2. Insert mode: Enter the content you want to edit, Press [ESC] to return to the command line mode, and press [:] (colon) to enter the last line mode
3. last line mode: save the text and enter the SAVE command or exit vi. enter "wq" to save the disk and exit vi, and enter "q !] Exit vi without saving. enter w: filename to save the file as the specified file name.