i was just wondering...

are there any advantages to castling king side vs. queen side?  or on the same or opposite side of the board as you opponent?

opposite side of your opponent allows for pawn storms at their castle structure

Yes. Big difference.

1. Queenside castling is more dangerous in general because the king does not protect the a file pawn after castling.

2. If you are behind in development you should castle on the same side as your opponent.

3. Opposite side castling generally leads to a race. Whoever punches through with their wing attack wins. So you need to make sure you don't fall behind. If you do you should have castled on the same side. See note  2.

4. Queen side castling lands the rook on a central (mostly open) file directly. You might consider this saving a move, but that move is lost mostly because you need to move your king to protect your a pawn mostly.

It all depends on the situation.  Basically, if your opponent is attacking your kingside, castle queenside; if your opponent is attacking your queenside, castle kingside.

so same side is more defesive (by avoiding opponent pawn storms)?

Yes, same side is more defensive. If you are losing, pressured or behind in development you need to castle same side. If you are in lead you should not do that ofcourse.

ok thanks.  i usually prefer king side just for defensive reasons anyway