I've set up Android on a virtualbox, it boots and runs correctly.
However I'm trying to start its console so I can do netcfg and get the IP address, so I can try connecting the adb to it.
As the tutorials say, I tried pressing ALT + F1 but it has no effect. I've tried both the right and left ALT buttons but the console doesn't show up.
What am I doing wrong? Does Android have to be started in Debug mode to see the console?
No need for Debug mode for use the console. What a image are you use? Try [Ctrl]+Alt+F2/F3, or download other image.
Easiest way it's to open the Android Apps inside the VM and open a Terminal Emulator like you will do in your phone. At least, I do it that way as ALT+F1 doesn't work for me. Then, in the terminal emulator, you can use "su" to root and "netcfg" to know the IP of the VM so as to use it in "adb connect IP". Hope it helps