Linux

A good start is to install tldr. You use it like man, but it gives you shorter explanations – or rather, a short list of illustrative examples.

As for man pages themselves (which I often find overwhelming, too), if you're not doing that already, you can pipe it into grep to extract just those lines that contain your search string:

man ps | grep user

# or for two lines of context above and below each match:
man ps | grep user -C 2 

Going further, check out Fish instead of Bash. I haven't use Fish yet, but it's said to be much better for learning Linux commands as a beginner. Later on, you may switch to Zsh. In any case, hitting Tab once or twice will often give you a list of possible completions to the command you are typing.

PS: I see no good reason why anyone should downvote this question.

Edit (June 23): As it so happens, just today I've stumbled into the O'Reilly book "Classic Shell Scripting" by Robbins and Beebe (ISBN 9780596005955). What can I say – its age notwithstanding, it's apparently an extremely good book for understanding things and learning how to solve real problems. (It presupposes some familiarity with Unix-like systems and with the shell, so if one's just starting out, the book "Learning the Unix Operating System" may be better.)