You can obtain coins and Gold Skate Wheels by playing the Bounce game. The game is played by moving your skateboard deck from left to right and bouncing skate wheels until they reach the safety of the table on the right side of the screen. You get 50 points for each skate wheel that is safely bounced this way.
If you get at least 1500 points before losing all of your lives, you will get a Gold Skate Wheel, which you can give to Olivia Kickflip in return for coins. The more points you earn, the higher chances you have of receiving more Gold Skate Wheels.