Do you want bottom dock like in OS X or elementary OS? If you are using GNOME Shell, then Dash to Dock by michele-g is the right extension for you. It helps you to turn the original left-vertical panel in GNOME Shell overview into a dock and control it freely. You even can put the dock in any position of your screen by this extension.
Follow our instructions about installing GNOME Shell Extension. Once installed, Dash to Dock will show itself in GNOME Tweak Tool (no icon on the top panel).
One of Dash to Dock basic purposes is to turn the left-vertical panel into bottom-horizontal dock. It is shown simply by its name, Dash to Dock. Just like the OS X bottom dock. To set it up, open your GNOME Tweak Tool > Extensions > Dash to dock > click the gear button > check the Bottom selection.
Then you will have the left-vertical panel (which only appears when the overview is on) moved to bottom as a dock and by default it will be in auto-hide mode. Touch the bottom edge of the screen and it will come.