Navigation is the whole skill of knowing where you are. cd moves you, pwd tells you, and ls shows what you can move into. Getting lost is not a failure, it is a state you should notice and fix in one command.
About 1 min of reading
Navigate and confirm at each step.
Make a nested folder
Before you run it, say out loud what it will print. Then open the answer.
Go back two levels
Before you run it, say out loud what it will print. Then open the answer.
cd My Docs fails because the shell splits at the space. Quote it, cd 'My Docs', or escape it. The failure is the shell doing its job correctly, which is why the fix is quoting rather than a different command.
A leading dot hides a file from a plain ls. Configuration lives there, which is why 'the file is not there' is often true and also the reason you are looking in the wrong place. Use ls -a when a dot file is suspected.
After every cd, run pwd or ls. Two seconds of work that removes the class of mistakes where you write a file in the wrong directory because you assumed you were somewhere else.
cd build/tmp is relative to where you are; cd /home/blue/build is not. Absolute paths do not care where you were, which makes them the right choice in a script and often in a terminal too.
cd - returns to the previous directory and cd ~ goes home. Both save the retyping that makes long paths error prone, and both are worth learning early because they change how much typing navigation costs.
Each one is defined here on this site. Open the entry for the full definition and the other words it points at.