castling early? why castle before you know what side they will attack?

I am finally learning chess.  I do not understand why castling early is so important.  example.  I develop early and castle king side. Lets say after 5 moves. Does that just let your opponent just set up first and attack that side?  Is  not better to wait as long as possible to see where their attack is heading?

600 ELO player at best

This is what I think as well. Taking too long to castle can be a bad thing, obviously, but there are times where taking a long time to castle (or even not castling at all) is perfectly fine.

The way I see it, castling should generally only be done if one of the following things is true:

1. Your opponent is attacking one side of the board heavily

2. The center is open(ing)

3. Your opponent is threatening to take away your castling rights and launch a big attack.

4. You just don't see a better move on the board.

Even if you lose the right to castle, it's not necessarily the end of the world. Take this position from one of my games, for example, where the loss of my castling rights didn't mean much:

I have played many games where I have lost castling rights, I think I am about 50% win-(but that goes with all games lol) I seem to agree that it is not the end all be all. I have watched more than a few GM games where neither Castled for well passed the 10-12 move range. I like your strategies on when to castle. thank you

Yes, it is okay to wait to castle & sometimes don't even castle at all. Real clever games can be waiting until your opponent castles before castling yourself. As long as your king is safe, get other moves done instead.

You should castle when you see that your king will be unsafe. Not when it's unsafe! When you see it WILL be unsafe. And you should not decide which side to castle by waiting for the opponent to see on which side he is attacking - because the good players only start attacking if you already castled/you cannot castle anymore. Instead, you should decide by examining the pawn structure and space on both sides. For example, you should not castle behind an open line. Another good way to decide where will you castle is by seeing on which side your opponent castles. If you want a safe game, castle on the same side (most of the time, although in the King's Indian, if you are with white, you can castle any side you will brutally get attacked). If you want a crazy, attacking game, castle on the opposite side!

I'd also like to add that there are rarely times where castling can be an attacking move as well.

See here:

Castling early, meaning somewhere near the transition to the middle game, is a golden principle for a very good reason. Failing to so will more often than not lead to completely avoidable difficulties. That being said, once a player has a solid grasp of a tactics and opening principles, they can become a more sophisticated player by delaying or not castling at all. Open games and open lines place a premium on castling quickly and to the "correct" side, closed games with few/no open files/diagonals results in little pressure to castle. Best way to learn about castling technique is to play 1.e4 gambits. Quickest way to lose an open game is to simply not castle. If you doubt this, simply play (50) 5/0 blitz 1.e4 e5 games --(25) as white and (25) as black--- and purposely do not castle, and see how successful you are.