Visual Studio keyboard shortcut to display IntelliSense

Ctrl+Space should do it.

Additionally, Ctrl + K, Ctrl + I shows you Quick info (handy inside parameters)

Ctrl+Shift+Space shows you parameter information.

The most efficient one is Ctrl + ..

It helps to automate insertions of using directives. It works if the focus is on a new identifier, e.g. class name.

Ctrl + Space

or

Ctrl + J

You can also go to menu Tools → Options → Environment → Keyboard and check what is assigned to these shortcuts. The command name should be Edit.CompleteWord.