Intermediate

Begin to feel the magic of Vim I guess

motion

e/E: go to the end of this word/Word
ge/gE : reverse of e/E
0/$: go to the start/end of the line
^ : go to the first non-blank char of line
g0/g$/g^: similar to 0/$/^, but targeting a wrapped line
gg/G: jump to the start/end of the file
<Number>G/<Number>gg: jump to nth line

change (normal-mode)

x/X: cut the char under/after cursor
s/S: cut the char under/after cursor and enter insert mode
r : replace the char under cursor
R : enter replace mode
a : append(insert) after cursor
I/A: insert/append(**insert before/after) the line
o/O : open a new line below/above and enter insert mode
*<< : add a indent to current line
*>> : remove a indent from current line
v: enter visual(select) mode to select part of code, then use y to yank(copy) the selected code

Insert (insert-mode)

Ctrl+n/Ctrl+p : select next/previous option in autocomplete or trigger default autocomplete behavior
Ctrl+w : delete word before cursor

Cmdline-mode

press <enter> after typing

:w <fileName>: overwrite/create fileName
:q! force quit without saving
ZZ : save and quit (= :x = :wq)
ZQ : force quit without saving (= :q!)
/<pattern> : search pattern
ctrl-l: to refresh (can be used to clear searching highlights)