i'm very new to studying chess.  i'm trying to play various openings against the computer, but i find the whole beginning of the game i'm playing counter position against black until i finally make a mistake.  i don't really know if this makes sense.

i guess i'm missing the point where i can make a plan and sacrifice pieces to gain an advantage in some way.  does anyone have any advice for this?  or should i just keep trying?

First of all, make sure you can consistently tie the computer, before you try to beat it.

If you can do that, I assure you that it is a much more difficult task to beat the computer in chess.  That depends on it making a mistake, and the computer is specifically designed not to make a mistake.  It will make mistakes, but there will not be refutations until 10 moves later, which are nearly impossible for humans to see at times.

Sacrificing material to gain a long-term advantage is generally a good idea.  If the computer cannot instantly see the position declining, it may accept the material, and you have essentially searched to a farther depth than the computer has.

However, to beat an extremely strong computer, you usually must be at GM level.  I am not, so I really can't help you any further.  Sorry.

Chess software is the best way to learn. It's a stone to sharpen your sword. Pay attention to how the computer sets up in the opening and use these methods yourself.

Computers are really good at stealing pieces too, if you play it often enough you will become good at stealing pieces.  Not a bad thing.

Sacrificing pieces against the computer is not a good idea.  Chess is all about learning when it's time to trade pieces of equal worth.  If you can see an advantage in doing so, whether material or positional, then it's time to trade.  Sometimes you might trade just to simplify the position.

One area where computers are weak is the pawns, they don't understand pawn structure so well. As you are new to the game this is something that will become clearer later on as it's the only way to defeat high level computerised opponents.

Just remember no matter how many times the computer defeats you its good for your overall game.  Don't get put off by that.