Trying to remember how it went - if you got the coin in your slice of breac, you would be the first of your siblings to get rich. If you got the ring, you would get engaged first. The stick was - I think - like getting coal in your Christmas stocking. I forget the symbolic meaning of the other tokens.
BTW breac means speckled.
Whether "put into" is better English than "put in" is a matter of debate - they are both grammatically correct English, with a slightly different meaning.
But "put into" is not a valid translation of Cuirtear fáinne sa bhairín breac. If the exercise was Cuirtear fáinne isteach sa bhairín breac then "A ring is put into the brack" would be correct.