Picking an opening and defense

So everything that I've seen says that I should pick one or two openings and defenses and get good at them.  But there are a good ton of them.  How do I pick which openings and which defenses I want to select to start with?

I would suggest reading up on the major openings and see which ones you feel best playing. When playing white, a major decision is whether to start with the king pawn or the queen pawn. Those choices result in very different kinds of games.

Personally I have a lot of trouble about openings because even if you learn a couple of openings really well, you can't control what the other person does, so if your opponent goes "off script," and you are relying on a choreographed opening, it can pull the rug out from under you. When learning an opening, I suggest that you understand the purpose of each particular move, rather than just memorizing the order of moves, because that way you are more ready to deal with surprises.

I am not sure that I have helped much, but those or some of my thoughts, and I hope someone else will offer something helpful.

For black, I am thinking that I am best off learning a few defenses, one for e4, one for d4 and one for other openings.

Also, what should I do if my opponent goes off-script?  Do I continue along with my planned opening as long as my path is not obstructed?