The essential components of the Friday night rituals are:
Candles - To be lit 18 minutes BEFORE sunset*
Kiddush - This is the blessing before drinking wine coupled with the blessing sanctifying the Sabbath.
Two Breads - This is commonly done with two loaves baked in the style referred to colloquially as "Challah". (In reality, the meaning of the word "Challah" is not related to this ritual, but to another, but that's a separate topic.)
That's basically it, except for a few accompanying rules.
A. Kiddush can only be fulfilled with an accompanying meal.
B. A "meal", for purposes of Kiddush, can be satisfied by eating a minimum amount of bread (or other grain product).
C. One must wash hands with a cup prior to making the HaMotzi blessing over the bread, which is required before one can eat the bread.
D. One must recite Grace After Meals upon concluding the (bread-based) "meal".
E. If one cannot make a proper Kiddush or eat a meal, one
can should recite the special prayers for Friday night, which include a form of the Kiddush.
F. The two breads should be covered while reciting Kiddush.
*G. It should be noted that, in a pinch, one can light an incandescent (and I've also heard even a florescent) light if candles are unavailable, prohibited, or dangerous (such as in a hospital room).