To find your active virtual terminal: fgconsole
Alternatively, use ps -ef | grep tty and identify what terminal you are on by using good old-fashioned thinking about it. (if youre using debian/X the GUI is probably 7)
To switch terminals using the command-line, chvt 1 will switch you to virtual terminal 1. Alternatively, use the keyboard with Ctrl+Alt+F1
On my keyboard, WinKey+F1 also works.
To switch terminals easily, use Alt+LeftArrow or Alt+RightArrow to switch sequentially through created virtual terminals.
This means, if you use Ctrl+Alt+F1, then Ctrl+Alt+F2, you can switch back and forth between them using the alt+arrow keys shortcut.
Linux Virtual Terminals