Queenside takes longer and doesn’t make the king “quite” as safe although you can move one more queenside to protect the three edge pawn. (Kingside castle requires an extra move to get the rook clear of the three pawn defense.) The advantage is the rook is often on an open file immediately. That rook can wreak havoc sometimes. Note castling opposite directions usually results in a “pawn storm” which you will have to deal with and probably do your own.

Not even GMs can predict the game past the opening otherwise the opening choice would decide the winner. The session tonight drove home you follow openings up until something disrupts it at which point you have to fall back on basic principles and “play chess”.