It's amazing that nearly every single command line tool comes with a manual via man , but navigating the man output can be sometimes a little confusing, plus it can be daunting given all the technical information that's included in the manual output.
htop is an improvement on both regular top and crappy-mac top. Lots of colour coding, keyboard bindings and different views which have helped me in the past to understand which processes belong to which.
Handy key bindings include:
P - sort by CPU M - sort by memory usage F4 - filter processes by string (to narrow to just "node" for instance) space - mark a single process so I can watch if the process is spiking
cat is used to print the contents of a file, but given more time spent in the command line, features like syntax highlighting come in very handy. I found ccat which offers highlighting then I found bat which has highlighting, paging, line numbers and git integration.
The bat command also allows me to search during output (only if the output is longer than the screen height) using the / key binding (similarly to less searching).