Bash commands not working on GitBash?

I am a relatively new programmer, and I am following a course which uses Bash for the majority of the exercises. I am running into several problems where Bash commands that instructor uses do not seem to work on Git Bash, and I cannot find any solutions on StackOverflow or in any articles. When I try using man, sudo, apt, apt-get, traceroute, GitBash returns command not found. It seems that there is a difference between Bash and GitBash, but for the life of me I can’t understand it. Any help how to fix this is much appreciated!

Most of the commands you listed are system commands that don’t work on windows.

As far as I know, all the commands are inside:

C:\Program Files\Git\usr\bin

For example, ls.exe