It's true that in Texas Hold'em any two cards can be a winner. But it's cards, not dice, and although luck plays a part in every hand, strategy can make you a long term winner.
Texas Hold'em is a game where you should pick and choose your battles wisely. Playing every hand will of course lead to winning more pots. But in between those wins will be more losses as well. Playing the right hands, at the right time will leave you with more chips in your stack.
That leads us to seat position. Timing is everything in some cases, and in poker it certainly counts for something. While some cards are playable under some circumstances, they aren't under others. Seat position is a key part of the circumstances that dictate whether you should play a hand, or wait for a better opportunity to present itself.
Professional poker players can sense what their opponents have in their hands. When just beginning you may not be able to read your opponents with that level of skill, but if you can take a moment to read the cards on the board, you can tell with certainty what they do not have. Reading the board lets you know what hands are possible, and from there you can use other information from your opponents to gauge what hands are probable. And act accordingly.
Often players will find themselves in need of a card to complete their hand. These hands are known as drawing hands. When on a drawing hand, it's nice to know what the odds of your ship actually coming in are. Armed with those odds, you're better able to play your hand correctly. So, see the drawing odds page for a chart that will tell you the odds of completing your gutshot straight, flush, or three-of-a-kind. Information is power at the table, and this information is part of the basic skills that winning poker players possess.
Related to drawing odds is the concept of pot odds. When you know you're waiting on a card to complete your hand, and there's a bet before you, you'd like to know if calling that bet is a good idea or a bad idea. If you're familiar with the concept of pot-odds, you'd be informed enough to make that decision. When you're ready to have that kind of power at the tables, read the primer on pot odds.