Get Skateboard
If you don't have a skateboard go left from your house to the intersection. Then go down across the road then keep going down. When you get to the corner go right. once you have gone a bit the Brickster will give you a skateboard.
Castle Island
Go to Darren's house and in his backyard you will find the Hospital page then go to the Hospital's mailbox. When you get there the patient will give you a ticket to Castle Island. Go to the Ferry Peir and a ferry will take you to Castle Island.
Hidden Card
Start at your house. Keep going left til you pass the clubhouse. Then go up until you get to a house. Then go where the door is, then down and right into the garden. Then go behind the house and you will find the hidden trading card.
Hint: Wrenches
Go south from the tunnel leading to the south part of the Island. Near the farm at the south part of the Island.