I want to start studying chess but one thing I'm having trouble with is the openings. I don't know what openings to use. Should I learn a bunch, then choose one randomly before a game, or should I choose a couple of openings and get good with those? Is there really a better thing to do or is it mostly based on personal preference?
Take the following factors into account:
roughly how many moves you can memorize (if you can't memorize 5 moves or so, at least avoid stuff like the Ruy Lopez)
style (don't play the King's Gambit if you are a positional player)
your ability to gauge whether an opening fits or doesn't fit any of the above (this is kind of an abstract concept)
Most people have their "favorite" openings. That's only natural, because people need to learn fewer openings.
One important thing to do is avoid your "unfavorite" openings. For instance, if you dislike playing Ruy Lopez as Black (as I do), learn non e5 openings such as the French and Sicilian defenses. And if you play e5, learn the Petroff Defense.
If you dislike Queen's Gambit Declined, play Queen's Gambit Accepted. Or learn the "Indian" openings.
I would say it's personal preference largely, yes. One thing I didn't see in the other answers though: consider the openings you're most likely to face from an opponent first, especially as black. It won't do a lot of good to "learn a bunch" and then find that you never end up facing most of them.
Try playing a couple of games with different openings. Learn their variations so you don't get bored playing a particular line continuously, failing to maximise the exploration process. With time, you will probably get comfortable playing certain openings and go on to build your opening repertoire. But try a lot of openings first, don't restrict yourself.
If you need help, you can go through openings and their variations on