Your Chromebook comes equipped with a slightly different layout from the keyboards you've used in the past. It has a dedicated Search key instead of a Caps Lock key, and also has a top row of shortcut keys to help you access common actions quickly.
The Search key is located where you'd find the Caps Lock key on a traditional keyboard, above the Shift key and below the Tab key. Press it to open a new tab with focus in the Omnibox so you can do a quick web search. If you'd like the Caps Lock key back, you can change this key inside the System section of the Settings. Note that if you have spoken feedback enabled, pressing Search will not open a new tab because Search is a ChromeVox modifier key.
The Control and Alt keys are located on the bottom row, on either side of the spacebar. See the Bottom Row section below for a full layout of the bottom row of the keyboard. The location of the Control and Alt keys can be changed in the ChromeVox settings.