You don't appear to have python3 on installed your computer, as pip3 comes pre-installed with python3 99.9% of the time. Here is a tutorial to install it: http://www.marinamele.com/2014/07/install-python3-on-mac-os-x-and-use-virtualenv-and-virtualenvwrapper.html

Ignore the part of the tutorial about pyvenv, which is a module that is unnecessary for my program.

You navigate in terminal by typing:

cd (path of directory)

(The above does not include the parentheses)

While I agree with your point about cryptocurrency adoption, most people who use the computer for more than browsing the internet are familiar with these tasks, and if they aren't, it doesn't take more than a quick google search to complete them. And yes, while we don't run DOS anymore, no matter what the operating system or the technological advancements we make in personal computing, the command line will always be essential to the computer.