For regular use, you'll want to plug the Raspberry Pi in to a visual display: a monitor or a TV.
The Raspberry Pi has a HDMI port which you can plug directly into a monitor or TV with an HDMI cable. This is the easiest solution; some modern monitors and TVs have HDMI ports, and some do not, but there are other options:
For monitors with a DVI port, you can use an HDMI-to-DVI cable.
For monitors with VGA only, you can use an HDMI-to-VGA adapter.
For analogue TVs you can use a standard RCA composite video lead.