At a command prompt, you can use the man command. Which is basically short for manual. For example:
That will pull up the man page on how to use vim. Just hit "q" to exit when you're done reading.
Personally, I find vim to be annoying. Fortunately in Linux land, we have lots of choice. I prefer nano over vim. If it's available to you, you will probably find that command-line text editor more straight forward to use than vim.
Most linux commands have a switch to pull up a quick list of help commands as well. Usually -h or even-?
For example.