The command prompt depends on which command prompt you want to learn. If I understand you correctly, you are talking about DOS system. In fact, DOS system is still a foundation of most computer systems. Not many orders. You can find the syntax and usage of these DOS commands on the internet, but there is a problem:

There are not many pure DOS systems in the current system, most of them are simplified DOS systems, and the functions provided are far less perfect than when DOS first started. In other words, now that you have learned DOS, the commands that can be used in the actual environment are simplified.