I'm new to elementary OS, I was using Linux Mint and now I'm moved to elementary OS since Juno was released.. I often use ctrl + w for close window in Linux Mint (It's default on Linux Mint), can I use this shortcut in Juno for close window? because when I see keyboard setting I dont have "Close Window" command in the list..
Ctrl-W - is normally the close-tab short-key, and it works in tabbed apps like browsers and file managers, the last-tab closed closing the program or defaulting to the startup tab; Files stays open when last tab is closed (a setting that can be also enabled in Firefox:
about:config, then set
Ctrl-T - is the complementary to the above: the open-new-tab short-key. The Juno terminal will not follow these two shortcuts thought.
And there is the universal Alt-F4 that applies to all windows whatsoever.
Ctrl-Q - operates like the above, closing all windows - with very rare exceptions: Epiphany, mentioned in @JayAurabind's comment.