You chose to lead the 9 of Spades. This
is correct. It is not a very informative lead,
but it is the best of the options you were given. It should tell your partner
that you don't have any higher Spades - because if you have an honour in
a suit, usually you lead a low card.
This sort of lead where you lead the highest card you have from a worthless suit is called TOP OF NOTHING.
So the 9 of Spades is placed face up on the table as the OPENING LEAD. The next thing to happen is that the partner of the Declarer, in this instance, North, becomes the DUMMYand has to put his cards face up on the table, in columns with the trump suit on his right. And from then on for the rest of this particular hand, the dummy is just that - dumb - and is not allowed to speak or indicate in any way what his partner should do. His cards are played by Declarer.
It might be easier for you to visualise the cards, if you took a pack of cards and sorted them into the appropriate hands as we discuss them. If you have your pack already separated into suits, it will take you less time. Then you can play out each card as I mention it, and turn them upside down once they are played. You can put the ones won lengthwise, and the ones lost crosswise, so you can easily see how many tricks you have won as you go along. Alternatively, you could print out from the set hand, and then strike off the cards as they are played, indicating by a Tick or Cross whether you had won or lost them.
Once the dummy is revealed, the Declarer normally takes a bit of time to study it, and to plan his campaign for winning tricks. Up until now, he has only had his partner's bidding to go on, and now he will see if he understood correctly what his partner was telling him.
By looking at the two hands together, Declarer can see that there are only 3 Clubs out - but one of those is the Ace, so he will lose one Club trick. He can also see that he will lose one Heart trick - because after they have been played once, he can trump. He can see that three tricks in Spades should win. The tricky suit is Diamonds, and if the King is in the wrong place, he might lose a Diamond trick - making 3 losers, and he would go down. But for the most part, he is optimistic about the chances of getting the contract.
9. I have said he is optimistic about winning the Spades, so what card will he be playing on this first trick, from the dummy hand.