The default runlevel used when your system boots can be found in the /etc/inittab file.
If you have a line in that file that looks like
then your system will boot to runlevel 3, which means Black Terminal Of Death, just the Infamous Blinking Cursed Cursor will appear on screen. One would wonder why, but some distribution still defaults to init3, while install process that detect a failure may as well "jump" to this init3 level supposedly to allow you to save the day.
Now, if you have a line that looks like
your system is set to boot into runlevel 5, that's the multiuser Super Graphic Mode, well, I mean the thing you work with a mouse in like you just expected it to be, that's all.
As root, change the runlevel number in this /etc/inittab file to set a different default. Save the file and restart your system to verify that it boots to the correct runlevel.
To switch runlevels from a console, go root and just do init 3 to go Text-Mode or init 5 to go X (graphic) mode
The actual graphic screen is actually located at F7: read: most system now have 4 virtual terminals that you can access with Ctrl-Alt-F1...4 and the Graphic one that you usually enjoy is at F7.
Since most of today's end-users are not using them, are just not even aware of their presence, and even less able to do anything with them, there is a wealth of OpenSource devs out there that want to drop them, since they require a lot of maintenance to stay up-to-date (theses consoles are Very Very old code, their character set is completely outdated) so don't be surprised if one day, n front of a frozen X-windows system, you believe you'll get out of it by killing xorg from the Virtual Console awaiting between F1 and F4: they are an endangered specie and probably will disappear soon from the generic "big" distros.